@misc{KoechyTielboerger2006, author = {K{\"o}chy, Martin and Tielb{\"o}rger, Katja}, title = {Hydrothermal time model of germination : parameters for 36 Mediterranean annual species based on a simplified approach}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12406}, year = {2006}, abstract = {Germination rates and germination fractions of seeds can be predicted well by the hydrothermal time (HTT) model. Its four parameters hydrothermal time, minimum soil temperature, minimum soil moisture, and variation of minimum soil moisture, however, must be determined by lengthy germination experiments at combinations of several levels of soil temperature and moisture. For some applications of the HTT model it is more important to have approximate estimates for many species rather than exact values for only a few species. We suggest that minimum temperature and variation of minimum moisture can be estimated from literature data and expert knowledge. This allows to derive hydrothermal time and minimum moisture from existing data from germination experiments with one level of temperature and moisture. We applied our approach to a germination experiment comparing germination fractions of wild annual species along an aridity gradient in Israel. Using this simplified approach we estimated hydrothermal time and minimum moisture of 36 species. Comparison with exact data for three species shows that our method is a simple but effective method for obtaining parameters for the HTT model. Hydrothermal time and minimum moisture supposedly indicate climate related germination strategies. We tested whether these two parameters varied with the climate at the site where the seeds had been collected. We found no consistent variation with climate across species, suggesting that variation is more strongly controlled by site-specific factors.}, language = {en} } @misc{KoechyWilson2004, author = {K{\"o}chy, Martin and Wilson, Scott D.}, title = {Variation in nitrogen deposition and available soil nitrogen in a forest-grassland ecotone in Canada}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-5768}, year = {2004}, abstract = {Regional variation in nitrogen (N) deposition increases plant productivity and decreases species diversity, but landscape- or local-scale influences on N deposition are less well-known. Using ion-exchange resin, we measured variation of N deposition and soil N availability within Elk Island National Park in the ecotone between grassland and boreal forest in western Canada. The park receives regionally high amounts of atmospheric N deposition (22 kg ha⁻¹ yr⁻¹). N deposition was on average higher ton clayrich luvisols than on brunisols, and areas burned 1 - 15 years previously received more atmospheric N than unburned sites. We suggest that the effects of previous fires and soil type on deposition rate act through differences in canopy structure. The magnitude of these effects varied with the presence of ungulate grazers (bison, moose, elk) and vegetation type (forest, shrubland, grassland). Available soil N (ammonium and nitrate) was higher in burned than unburned sites in the absence of grazing, suggesting an effect of deposition. On grazed sites, differences between fire treatments were small, presumably because the removal of biomass by grazers reduced the effect of fire. Aspen invades native grassland in this region, and our results suggest that fire without grazing might reinforce the expansion of forest into grassland facilitated by N deposition.}, language = {en} } @misc{Laschewsky1995, author = {Laschewsky, Andr{\´e}}, title = {Molecular concepts, self-organisation and properties of polysoaps}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26895}, year = {1995}, abstract = {The article reviews water-soluble polymers characterized by surfactant side chains, and related amphiphilic polymers. Various synthetic approaches are presented, and rules for useful molecular architectures are given. Models for the self-organization of such polymers in water are presented comparing them with the micellization of low molecular weight surfactants. Highlighting key properties of aqueous polysoap solutions such as viscosity, surface tension and solubilization power, some structure-property relationships are established. Further, the formation of mesophases and of superstructures in bulk is addressed. Finally, the functionalization of polysoaps, and potential applications are discussed.}, language = {en} } @misc{Laschewsky1989, author = {Laschewsky, Andr{\´e}}, title = {Monolayers and Langmuir-Blodgett multilayers of discotic liquid crystals?}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17396}, year = {1989}, abstract = {Contents: 1. Discotic Liquid Crystals 2. Monolayers and Langmuir-Blodgett Multilayers 3. Theoretical Considerations on the Molecular Packing of Discotic LCs in Monolayers and Multilayers 4. Spreading Experiments with Discotic LCs 5. LB-Multilayers of Discotic LCs 6. Polymeric Discotic LCs 7. Summary}, language = {en} } @misc{Laschewsky1991, author = {Laschewsky, Andr{\´e}}, title = {Oligoethyleneoxide spacer groups in polymerizable surfactants}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17221}, year = {1991}, abstract = {Cationic and zwitterionic polymerizable surfactants bearing tri- and tetraethyleneglycol spacer groups between the polymerizable moiety and the surfactant structure were prepared and polymerized. Monomers and polymers were investigated with respect to their aggregation behavior in aqueous systems and compared to analogous monomers and polymers lacking spacer groups. In the case of the monomeric surfactants, the spacer groups depress both the Kraffttemperature and the critical micelle concentration. the area occupied per molecule at the air-water interface is substantially enlarged by the spacers, whereas the depression of surface tension is nearly constant. Although the monomers with and without spacers are true surfactants, all the polymers are water-insoluble, but form monomolecular layers at the air-water interface. In analogy to the monomer behavior, the incorporation of the spacer groups increases the area occupied per repeat unit at the air-water interface substantially, but hardly affects the surface activity.}, language = {en} } @misc{LaschewskyPaulusRingsdorfetal.1992, author = {Laschewsky, Andr{\´e} and Paulus, Wolfgang and Ringsdorf, Helmut and Schuster, A. and Frick, G. and Mathy, A.}, title = {Mixed polymeric monolayers and Langmuir-Blodgett multilayers with functional low molecular weight guest compounds}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17233}, year = {1992}, abstract = {Mixed monolayers and Langmuir-Blodgett multilayers of functional low molecular weight guest compounds, especially nonlinear optical (NLO) dyes, within the matrix of an amphotropic spacer polymer have been prepared. The polymer matrix enabled the transfer of guest compounds not capable of self-organizing at the air-water interface by themselves. The structure of the LB multilayers and the transfer process were studied by small angle X-ray scattering and UV-visible spectroscopy. Good NLO coefficients were found in the mixed films.}, language = {en} } @misc{LaschewskyRingsdorf1988, author = {Laschewsky, Andr{\´e} and Ringsdorf, H.}, title = {Polymerization of amphiphilic dienes in Langmuir-Blodgett multilayers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17176}, year = {1988}, abstract = {Amphiphilic derivatives of octadiene and docosadiene were investigated in monolayers and Langmuir-Blodgett multilayers, with respect to their self-organization and their polymerization behavior. All amphiphiles investigated form monolayers. However, only acid and alcohol derivatives were able to build up multilayers. Those multilayers are rapidly photopolymerized in the layers via a two-step process: Irradiation with long-wavelength UV light yields soluble polymers, whereas additional irradiation with sfiort-wavelength UV light produces insoluble and presumably cross-linked polymers. The reaction meclianism is discussed according to the polymer characterization by UV spectroscopy, small-angle X-ray scattering, NMR spectroscopy, and gel permeation chromatography. All multilayers undergo structural changes during the polymerization; substantial changes result in defects in the polymerized layers as observed by scanning electron microscopy. In contrast to the acids and alcohols, the deposition of monolayers of the aldehyde derivatives did not yield well-ordered multilayers, but rather amorphous films. In this different film structure, the photopolymerization process differs from the one observed in multilayers.}, language = {en} } @misc{LaschewskyRingsdorfSchmidt1985, author = {Laschewsky, Andr{\´e} and Ringsdorf, H. and Schmidt, G.}, title = {Polymerization of hydrocarbon and fluorocarbon amphiphiles in Langmuir-Blodgett multilayers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17096}, year = {1985}, abstract = {Langmuir-Blodgett multilayers of polymerizable carboxylic acids with hydrocarbon or fluorocarbon chains were prepared. The multilayers were polymerized by UV light and the reactions were studied by UV/visible spectroscopy. The polyreactions strongly influence the multilayer structures which were investigated by X-ray small-angle scattering and scanning electron microscopy. The spreading behaviour of the monomers, the preparation of multilayers, their reactivities in multilayers and structural effects caused by the polyreactions are discussed with regard to the hydrophilic head groups, the polymerizable groups and the hydrophobic chains.}, language = {en} } @misc{LaschewskyRingsdorfSchmidtetal.1987, author = {Laschewsky, Andr{\´e} and Ringsdorf, H. and Schmidt, G. and Schneider, J.}, title = {Self-organization of polymeric lipids with hydrophilic spacers in side groups and main chain : investigation in monolayers and multilayers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17147}, year = {1987}, abstract = {Several polymerizable lipids were synthesized and polymerized to amphiphilic homopolymers and to copolymers with the help of hydrophilic comonomers. The self-organization of these polymeric lipids was investigated in monolayers and Langmuir-Blodgett multilayers. The self-organization of these polymers in model membranes is due to hydrophilic spacer groups in the amphiphilic side groups as well as to hydrophilic spacer groups in the polymer backbone. Thus, highly ordered monolayers and LB-multilayers are easily obtained.}, language = {en} } @misc{LaschewskyRingsdorfSchneider1986, author = {Laschewsky, Andr{\´e} and Ringsdorf, H. and Schneider, J.}, title = {Oriented supramolecular systems-polymeric monolayers and multilayers from prepolymerized amphiphiles}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17131}, year = {1986}, abstract = {Oriented polymeric membranes were originally prepared by polymerization or polycondensation of preoriented monomers. The introduction of hydrophilic spacer groups into the polymeric amphiphiles allowed the formation of highly ordered systems (monolayers, liposomes, multilayers) from prepolymerized amphiphiles: due to the partial decoupling of the different mobilities and orientation tendencies of the polymer chain and the amphiphilic side groups, these polymers are able to self-organize. In monolayer experiments the high order of these membranes could be demonstrated by their surface pressure area-diagrams. In addition the combination of order and mobility of these spacer groups containing polymeric amphiphiles allowed the formation of Langmuir-Blodgett-multilyers with a high layer correlation. Thus, disturbancies in highly oriented layers can be avoided normally taking place during the polymerization reaction (e.g. contractions) or oriented monomeric layers.}, language = {en} } @misc{LaschewskySchulzHanke1993, author = {Laschewsky, Andr{\´e} and Schulz-Hanke, Wolfgang}, title = {Ring-opening metathesis polymerization of amphiphilic norbornenes functionalized with non-linear optical (NLO) chromophores}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26917}, year = {1993}, abstract = {Contents: Potential of amphiphilic NLO polymers Ring-opening metathesis polymerization (ROMP) Properties of the polymers Monolayer properties Experimental part - Methods - Materials - Analytical data - General polymerization procedure Conclusions}, language = {en} } @misc{LattemannKupkeStieglitzetal.2007, author = {Lattemann, Christoph and Kupke, S{\"o}ren and Stieglitz, Stefan and Fetscherin, Marc}, title = {The governance of virtual corporations}, issn = {1867-5808}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19988}, year = {2007}, abstract = {The concept of the virtual corporation (VC), which describes a modern form of collaboration among organizations, was introduced in the scientific discussion in the mid 1990th. The practice shows that VCs need new forms of governance because the traditional mechanisms of control, management, and steering are hardly applicable. Until now there is only a few research related to the question how to govern VC. The main problems to govern a VC are to coordinate the communication among dispersed partners and to motivate employees to actively involve themselves into the network. Open source projects are confronted with similar problems. As several governance mechanisms are already analyzed in this context, the authors analyze and adopt governance concepts from open source projects to extract a governance framework for virtual corporations. This new approach leads to innovative insights in governing virtual corporations by using community techniques as an appropriate way for communication and collaboration purposes.}, language = {en} } @misc{LattemannStieglitz2005, author = {Lattemann, Christoph and Stieglitz, Stefan}, title = {Framework for Governance in Open Source Communities}, issn = {1867-5808}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19941}, year = {2005}, abstract = {In recent years, the development of software in open source communities has attracted immense attention from research and practice. The idea of commercial quality, free software, and open source code accelerated the development of well-designed open source software such as Linux, Apache tools, or Perl. Intrinsic motivation, group identification processes, learning, and career concerns are the key drivers for a successful cooperation among the participants. These factors and most mechanisms of control, coordination, and monitoring forms of open source communities can hardly be explained by traditional organizational theories. In particular, the micro and macro structures of open source communities and their mode of operation are hardly compatible with the central assumption of the New Institutional Theory, like opportunistic behavior. The aim of this contribution is to identify factors that sustain the motivation of the community members over the entire life cycle of an open source project. Adequate coordination and controlling mechanisms for the governance in open source communities may be extracted.}, 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} } @misc{LeimkuhlerReich1994, author = {Leimkuhler, Benedict and Reich, Sebastian}, title = {Symplectic integration of constrained Hamiltonian systems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15653}, year = {1994}, abstract = {A Hamiltonian system in potential form (formula in the original abstract) subject to smooth constraints on q can be viewed as a Hamiltonian system on a manifold, but numerical computations must be performed in Rn. In this paper methods which reduce "Hamiltonian differential algebraic equations" to ODEs in Euclidean space are examined. The authors study the construction of canonical parameterizations or local charts as well as methods based on the construction of ODE systems in the space in which the constraint manifold is embedded which preserve the constraint manifold as an invariant manifold. In each case, a Hamiltonian system of ordinary differential equations is produced. The stability of the constraint invariants and the behavior of the original Hamiltonian along solutions are investigated both numerically and analytically.}, language = {en} } @misc{LemkeFernandezTrujilloLoehmannsroeben2005, author = {Lemke, Matthias and Fern{\´a}ndez-Trujillo, Rebeca and L{\"o}hmannsr{\"o}ben, Hans-Gerd}, title = {In-situ LIF analysis of biological and petroleum-based hydraulic oils on soil}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12268}, year = {2005}, abstract = {Absorption and fluorescence properties of 4 hydraulic oils (3 biological and 1 petroleum-based) were investigated. In-situ LIF (laser-induced fluorescence) analysis of the oils on a brown sandy loam soil was performed. With calibration, quantitative detection was achieved. Estimated limits of detection were below ca. 500 mg/kg for the petroleum-based oil and ca. 2000 mg/kg for one biological oil. A semi-quantitative classification scheme is proposed for monitoring of the biological oils. This approach was applied to investigate the migration of a biological oil in soil-containing compartments, namely a soil column and a soil bed.}, language = {en} } @misc{LindenbergerKlieglBates1992, author = {Lindenberger, Ulman and Kliegl, Reinhold and Bates, Paul B.}, title = {Professional expertise does not eliminate age differences in imagery-based memory performance during adulthood}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-40384}, year = {1992}, abstract = {Using a testing-the-limits paradigm, the authors investigated the modulation (attenuation) o f negative adult age differences in imagery-based memory performance as a function of professional expertise. Six older graphic designers, 6 normal older adults, 6 younger graphic design students, and 6 normal younger students participated in a 19-session program with a cued-recall variant of the Method of Loci. Older graphic designers attained higher levels o f mnemonic performance than normal older adults but were not able to reach younger adults' level of performance; a perfect separation of age groups was achieved. Spatial visualization was a good predictor of mnemonic performance. Results suggest that negative adult age differences in imagery-based memory are attenuated but not eliminated by the advantages associated with criterion-relevant ability (talent) and experience.}, language = {en} } @misc{LindenbergerMayrKliegl1993, author = {Lindenberger, Ulman and Mayr, Ulrich and Kliegl, Reinhold}, title = {Speed and intelligence in old age}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-40402}, year = {1993}, abstract = {Past research suggests that age differences in measures of cognitive speed contribute to differences in intellectual functioning between young and old adults. To investigate whether speed also predicts age-related differences in intellectual performance beyond age 70 years, tests indicating 5 intellectual abilities—speed, reasoning, memory, knowledge, and fluency—were administered to a close-to-representative, age-stratified sample of old and very old adults. Age trends of all 5 abilities were well described by a negative linear function. The speed-mediated effect of age fully explained the relationship between age and both the common and the specific variance of the other 4 abilities. Results offer strong support for the speed hypothesis of old age cognitive decline but need to be qualified by further research on the reasons underlying age differences in measures of speed.}, language = {en} } @misc{LindenmaierZeheDittfurthetal.2004, author = {Lindenmaier, Falk and Zehe, Erwin and Dittfurth, Angela and Ihringer, J{\"u}rgen}, title = {Process identification at a slow-moving landslide in the Vorarlberg Alps}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60226}, year = {2004}, abstract = {A fine-grained slope that exhibits slow movement rates was investigated to understand how geohydrological processes contribute to a consecutive development of mass movements in the Vorarlberg Alps, Austria. For that purpose intensive hydrometeorological, hydrogeological and geotechnical observations as well as surveying of surface movement rates were conducted during 1998-2001. Subsurface water dynamics at the creeping slope turned out to be dominated by a three-dimensional pressure system. The pressure reaction is triggered by fast infiltration of surface water and subsequent lateral water flow in the south-western part of the hillslope. The related pressure signal was shown to propagate further downhill, causing fast reactions of the piezometric head at 5Ð5 m depth on a daily time scale. The observed pressure reactions might belong to a temporary hillslope water body that extends further downhill. The related buoyancy forces could be one of the driving forces for the mass movement. A physically based hydrological model was adopted to model simultaneously surface and subsurface water dynamics including evapotranspiration and runoff production. It was possible to reproduce surface runoff and observed pressure reactions in principle. However, as soil hydraulic functions were only estimated on pedotransfer functions, a quantitative comparison between observed and simulated subsurface dynamics is not feasible. Nevertheless, the results suggest that it is possible to reconstruct important spatial structures based on sparse observations in the field which allow reasonable simulations with a physically based hydrological model. Copyright  2005 John Wiley \& Sons, Ltd. KEY WORDS rainfall-induced landslides; soil creep; hydrological modelling; Vorarlberg; Austria; pressure propagation}, language = {en} } @misc{Louis2004, author = {Louis, Pierre-Yves}, title = {Ergodicity of PCA}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6589}, year = {2004}, abstract = {For a general attractive Probabilistic Cellular Automata on S-Zd, we prove that the (time-) convergence towards equilibrium of this Markovian parallel dynamics, exponentially fast in the uniform norm, is equivalent to a condition (A). This condition means the exponential decay of the influence from the boundary for the invariant measures of the system restricted to finite boxes. For a class of reversible PCA dynamics on {1,+1}(Zd), wit a naturally associated Gibbsian potential rho, we prove that a (spatial-) weak mixing condition (WM) for rho implies the validity of the assumption (A); thus exponential (time-) ergodicity of these dynamics towards the unique Gibbs measure associated to rho hods. On some particular examples we state that exponential ergodicity holds as soon as there is no phase transition.}, subject = {Wahrscheinlichkeitstheorie}, language = {en} } @misc{LupoPrassScheunemannetal.1988, author = {Lupo, Donald and Prass, Werner and Scheunemann, Ude and Laschewsky, Andr{\´e} and Ringsdorf, Helmut and Ledoux, Isabelle}, title = {Second-harmonic generation in Langmuir-Blodgett monolayers of stilbazium salt and phenylhydrazone dyes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17401}, year = {1988}, abstract = {Contents: 1. INTRODUCTION 2. SYNTHESIS OF THE COMPOUNDS 3. PREPARATION AND CHARACTERIZATION OF MONOLAYERS A. Monolayer Isotherms B. Langmuir-Blodgett Monolayer Films 4. EXPERIMENTAL SETUP FOR NONLINEAR MEASUREMENTS 5. NONLINEAR OPTICAL PROPERTIES 6. DISCUSSION 7. CONCLUSION}, language = {en} } @misc{LoehmannsroebenBeckHildebrandtetal.2006, author = {L{\"o}hmannsr{\"o}ben, Hans-Gerd and Beck, Michael and Hildebrandt, Niko and Schm{\"a}lzlin, Elmar and van Dongen, Joost T.}, title = {New challenges in biophotonics : laser-based fluoroimmuno analysis and in-vivo optical oxygen monitoring}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10120}, year = {2006}, abstract = {Two examples of our biophotonic research utilizing nanoparticles are presented, namely laser-based fluoroimmuno analysis and in-vivo optical oxygen monitoring. Results of the work include significantly enhanced sensitivity of a homogeneous fluorescence immunoassay and markedly improved spatial resolution of oxygen gradients in root nodules of a legume species.}, subject = {Sauerstoff}, language = {en} } @misc{LoehmannsroebenBeitzLuadienetal.2004, author = {L{\"o}hmannsr{\"o}ben, Hans-Gerd and Beitz, Toralf and Luadien, Robert and Schultze, Rainer}, title = {Laser-based ion mobility spectrometry for sensing of aromatic compounds}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-11892}, year = {2004}, abstract = {The drift time spectra of polycyclic aromatic hydrocarbons (PAH), alkylbenzenes and alkylphenylethers were recorded with a laser-based ion mobility (IM) spectrometer. The ion mobilities of all compounds were determined in helium as drift gas. This allows the calculation of the diffusion cross sections (Omegacalc) on the basis of the exact hard sphere scattering model (EHSSM) and their comparison with the experimentally determined diffusion cross sections (Omegaexp). These Omegaexp/Omegacalc-correlations are presented for molecules with a rigid structure like PAH and prove the reliability of the theoretical model and experimental method. The increase of the selectivity of IM spectrometry is demonstrated using resonance enhanced multiphoton ionisation (REMPI) at atmospheric pressure, realized by tuneable lasers. The REMPI spectra of nine alkylbenzenes and alkylphenylethers are investigated. On the basis of these spectra, the complete qualitative distinction of eight compounds in a mixture is shown. These experiments are extended to alkylbenzene isomer mixtures.}, language = {en} } @misc{MacWhinneyBatesKliegl1984, author = {MacWhinney, Brian and Bates, Elizabeth and Kliegl, Reinhold}, title = {Cue validity and sentence interpretation in English, German, and Italian}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16847}, year = {1984}, abstract = {Linguistic and psycholinguistic accounts based on the study of English may prove unreliable as guides to sentence processing in even closely related languages. The present study illustrates this claim in a test of sentence interpretation by German-, Italian-, and English-speaking adults. Subjects were presented with simple transitive sentences in which contrasts of (1) word order, (2) agreement, (3) animacy, and (4) stress were systematically varied. For each sentence, subjects were asked to state which of the two nouns was the actor. The results indicated that Americans relied overwhelming on word order, using a first-noun strategy in NVN and a second-noun strategy in VNN and NNV sentences. Germans relied on both agreement and animacy. Italians showed extreme reliance on agreement cues. In both German and Italian, stress played a role in terms of complex interactions with word order and agreement. The findings were interpreted in terms of the "competition model" of Bates and MacWhinney (in H. Winitz (Ed.), Annals of the New York Academy of Sciences Conference on Native and Foreign Language Acquisition. New York: New York Academy of Sciences, 1982) in which cue validity is considered to be the primary determinant of cue strength. According to this model, cues are said to be high in validity when they are also high in applicability and reliability.}, language = {en} } @misc{MardoukhiJeonMetzler2015, author = {Mardoukhi, Yousof and Jeon, Jae-Hyung and Metzler, Ralf}, title = {Geometry controlled anomalous diffusion in random fractal geometries}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {980}, issn = {1866-8372}, doi = {10.25932/publishup-47486}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-474864}, pages = {30134 -- 30147}, year = {2015}, abstract = {We investigate the ergodic properties of a random walker performing (anomalous) diffusion on a random fractal geometry. Extensive Monte Carlo simulations of the motion of tracer particles on an ensemble of realisations of percolation clusters are performed for a wide range of percolation densities. Single trajectories of the tracer motion are analysed to quantify the time averaged mean squared displacement (MSD) and to compare this with the ensemble averaged MSD of the particle motion. Other complementary physical observables associated with ergodicity are studied, as well. It turns out that the time averaged MSD of individual realisations exhibits non-vanishing fluctuations even in the limit of very long observation times as the percolation density approaches the critical value. This apparent non-ergodic behaviour concurs with the ergodic behaviour on the ensemble averaged level. We demonstrate how the non-vanishing fluctuations in single particle trajectories are analytically expressed in terms of the fractal dimension and the cluster size distribution of the random geometry, thus being of purely geometrical origin. Moreover, we reveal that the convergence scaling law to ergodicity, which is known to be inversely proportional to the observation time T for ergodic diffusion processes, follows a power-law ∼T-h with h < 1 due to the fractal structure of the accessible space. These results provide useful measures for differentiating the subdiffusion on random fractals from an otherwise closely related process, namely, fractional Brownian motion. Implications of our results on the analysis of single particle tracking experiments are provided.}, language = {en} } @misc{MayrKliegl1993, author = {Mayr, Ulrich and Kliegl, Reinhold}, title = {Sequential and coordinative complexity : age-based processing limitations in figural transformations}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-40416}, year = {1993}, abstract = {Dimensions of cognitive complexity in figural transformations were examined in the context of adult age differences. Sequential complexity was manipulated through figural transformations of single objects in a multiple-object array. Coordinative complexity was induced through spatial or nonspatial transformations of the entire array. Results confirmed the prediction that age-related slowing is larger in coordinative complexity than in sequential complexity conditions. The effect was stable across 8 sessions (Experiment 1), was obtained when age groups were equated in accuracy with criterion-referenced testing (Experiment 2), and was corroborated by age-differential probabilities of error types (Experiments 1 and 2). A model is proposed attributing age effects under coordinative complexity to 2 factors: (a) basic-level slowing and (b) time-consuming reiterations through the processing sequence due to age-related working memory failures.}, language = {en} } @misc{MingKlieglShuetal.2010, author = {Ming, Yan and Kliegl, Reinhold and Shu, Hua and Pan, Jinger and Zhou, Xiaolin}, title = {Parafoveal Load of Word N+1 Modulates Preprocessing Effectivenessof Word N+2 in Chinese Reading}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57103}, year = {2010}, abstract = {Preview benefits (PBs) from two words to the right of the fixated one (i.e., word N+2)and associated parafoveal-on-foveal effects are critical for proposals of distributed lexical processing during reading. This experiment examined parafoveal processing during reading of Chinese sentences, using a boundary manipulation of N+2-word preview with low- and high-frequency words N+1. The main findings were (a) an identity PB for word N+2 that was (b) primarily observed when word N+1 was of high frequency (i.e., an interaction between frequency of word N+1 and PB for word N+2), and (c) a parafoveal-on-foveal frequency effect of word N+1 for fixation durations on word N. We discuss implications for theories of serial attention shifts and parallel distributed processing of words during reading.}, language = {en} } @misc{Mkandawire2014, author = {Mkandawire, Thandika}, title = {The death of Mandela and Africa's liberation struggle}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69964}, year = {2014}, abstract = {The name Mandela became first inscribed in the annals of African liberation as nothing particularly unusual at the time. The late fifties was an era of trials and detentions in the colonies. The Treason Trial, which took place from 1956 to 1961, was closely followed by those of my generation largely through Drum Magazine.}, language = {en} } @misc{MuscholPueschelHuelsmannetal.1991, author = {Muschol, Waldemar and P{\"u}schel, Gerhard Paul and H{\"u}lsmann, Martina and Jungermann, Kurt}, title = {Eicosanoid-mediated increase in glucose and lactate output as well as decrease and redistribution of flow by complement-activated rat serum in perfused rat liver}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45892}, year = {1991}, abstract = {Rat serum, in which the complement sytem had been activated by incubation with zymosan, increased the glucose and lactate output, and reduced and redistributed the flow in isolated perfused rat liver clearly more than the control serum. Heat inactivation of the rat serum prior to zymosan incubation abolished this difference. Metabolic and hemodynamic alterations caused by the activated serum were dose dependent. They were almost completely inhibited by the cyclooxygenase inhibitor indomethacin and by the thromboxane antagonist 4-[2-(4-chlorobenzenesulfonamide)-ethyl]-benzene-acetica cid (BM 13505), but clearly less efficiently by the 5'-lipoxygenase inhibitor nordihydroguaiaretic acid and the leukotriene antagonist N-{3-[3-(4-acetyl-3-hydroxy-2-propyl-phenoxy)-propoxy]-4-chlorine-6-methyl-phenyl}-1H-tetrazole-5-carboxamide sodium salt (CGP 35949 B). Control serum and to a much larger extent complement-activated serum, caused an overflow of thromboxane B₂ and prostaglandin F₂α into the hepatic vein. It is concluded that the activated complement system of rat serum can influence liver metabolism and hemodynamics via release from nonparenchymal liver cells of thromboxane and prostaglandins, the latter of which can in turn act on the parenchymal cells.}, language = {en} } @misc{Nateghpour2004, author = {Nateghpour, Mohamad Javad}, title = {Islamic councils and social democracy in Iran}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-47145}, year = {2004}, abstract = {For the first time when the new Islamic councils began their Operation, many intellectuals and politicians proclaimed that there would be no room for the young Islamic councils to proceed. In political terms, because of the new challenges between the rightists and leftists, many people had no hope to see the results of the councils. Still others believed that under the dominating ruling system of Iran there is no space for public opinion and participation in local decision-making. This paper focuses on the role of the Islamic Councils as a new form of social democracy, which decentralizes power and creates good local governance. The paper also discusses the obstacles for the Councils in the development of the region.}, language = {en} } @misc{NeuschaeferRubeDeVriesHaeneckeetal.1994, author = {Neusch{\"a}fer-Rube, Frank and DeVries, Christa and H{\"a}necke, Kristina and Jungermann, Kurt and P{\"u}schel, Gerhard Paul}, title = {Molecular cloning and expression of a prostaglandin E₂ receptor of the EP₃ϐ subtype from rat hepatocytes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45830}, year = {1994}, abstract = {Rat hepatocytes have previously been reported to possess prostaglandin E₂ receptors of the EP₃-type (EP₃-receptors) that inhibit glucagonstimulated glycogenolysis by decreasing cAMP. Here, the isolation of a functional EP₃ϐ receptor cDNA clone from a rat hepatocyte cDNA library is reported. This clone can be translated into a 362-amino-acid protein, that displays over 95\% homology to the EP₃ϐ receptor from mouse mastocytoma. The amino- and carboxy-terminal region of the protein are least conserved. Transiently transfected HEK 293 cells expressed a single binding site for PGE₂ with an apparent Kd of 15 nM. PGE₂ > PGF₂α > PGD₂ competed for [³H]PGE₂ binding sites as did the EP₃ receptor agonists M\&B 28767 = sulprostone > misoprostol but not the EP₁ receptor antagonist SC 19220. In stably transfected CHO cells M\&B 28767 > sulprostone = PGE₂ > misoprostol > PGF₂α inhibited the forskolin-elicited cAMP formation. Thus, the characteristics of the EP₃ϐ receptor of rat hepatocytes closely resemble those of the EP₃ϐ receptor of mouse mastocytoma.}, language = {en} } @misc{NeuschaeferRubePueschelJungermann1993, author = {Neusch{\"a}fer-Rube, Frank and P{\"u}schel, Gerhard Paul and Jungermann, Kurt}, title = {Characterization of prostaglandin-F₂α-binding sites on rat hepatocyte plasma membranes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45863}, year = {1993}, abstract = {Prostaglandin (PG)F₂α has previously been shown to increase glucose output from perfused livers and isolated hepatocytes, where it stimulated glycogen phosphorylase via an inositol-trisphosphatedependent signal pathway. In this study, PGF₂α binding sites on hepatocyte plasma membranes, that might represent the putative receptor, were characterized. Binding studies could not be performed with intact hepatocytes, because PGF₂α accumulated within the cells even at 4°C. The intracellular accumulation was an order of magnitude higher than binding to plasma membranes. Purified hepatocyte plasma membranes had a high-affinity/low-capacity and a low-affinity/highcapacity binding'site for PGF₂α. The respective binding constants for the high-affinity site were Kd = 3 nM and Bmax = 6 fmol/mg membrane protein, and for the low-affinity site Kd = 426 nM and Bmax = 245 fmol/mg membrane protein. Specific PGF₂α binding to the low-affinity site, but not to the high-affinity site, could be enhanced most potently by GTP[γS] followed by GDP[ϐS] and GTP, but not by ATP[γS] or GMP. PGF₂α competed most potently with [³H]PGF₂α for specific binding to hepatocyte plasma membranes, followed by PGD₂ and PGE₂. Since the low-affinity PGF₂α-binding site had a Kd in the concentration range in which PG had previously been shown to be half-maximally active, and since this binding site showed a sensitivity to GTP, it is concluded that it might represent the receptor involved in the PGF₂α signal chain in hepatocytes. A biological function of the high-affinity site is currently not known.}, language = {en} } @misc{NiederkruegerSalbBecketal.2006, author = {Niederkr{\"u}ger, Matthias and Salb, Christian and Beck, Michael and Hildebrandt, Niko and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Marowsky, Gerd}, title = {Improvement of a fluorescence immunoassay with a compact diode-pumped solid state laser at 315 nm}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-10150}, year = {2006}, abstract = {We demonstrate the improvement of fluorescence immunoassay (FIA) diagnostics in deploying a newly developed compact diode-pumped solid state (DPSS) laser with emission at 315 nm. The laser is based on the quasi-three-level transition in Nd:YAG at 946 nm. The pulsed operation is either realized by an active Q-switch using an electro-optical device or by introduction of a Cr4+:YAG saturable absorber as passive Q-switch element. By extra-cavity second harmonic generation in different nonlinear crystal media we obtained blue light at 473 nm. Subsequent mixing of the fundamental and the second harmonic in a β-barium-borate crystal provided pulsed emission at 315 nm with up to 20 μJ maximum pulse energy and 17 ns pulse duration. Substitution of a nitrogen laser in a FIA diagnostics system by the DPSS laser succeeded in considerable improvement of the detection limit. Despite significantly lower pulse energies (7 μJ DPSS laser versus 150 μJ nitrogen laser), in preliminary investigations the limit of detection was reduced by a factor of three for a typical FIA.}, subject = {Immunoassay}, language = {en} } @misc{OliveiraJrGueddariMoerschbacheretal.2008, author = {Oliveira Jr, E. N. and Gueddari, Nour E. El and Moerschbacher, Bruno M. and Peter, Martin and Franco, Telma}, title = {Growth of phytopathogenic fungi in the presence of partially acetylated chitooligosaccharides}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-42646}, year = {2008}, abstract = {Four phytopathogenic fungi were cultivated up to six days in media containing chitooligosaccharide mixtures differing in average DP and FA. The three different mixtures were named Q3 (which contained oligosaccharides ofDP2-DP10, withDP2-DP7 asmain components), Q2 (which contained oligosaccharides of DP2-DP12, with DP2-DP10 as main components) and Q1 (which derived from Q2 and contained oligomers of DP5-DP8 with hexamer and a heptamer as the main components). The novel aspect of this work is the description of the effect of mixtures of oligosaccharides with different and known composition on fungal growth rates. The growth rate of Alternaria alternata and Rhizopus stolonifer was initially inhibited by Q3 and Q2 at higher concentrations. Q1 had a growth stimulating effect on these two fungi. Growth of Botrytis cinerea was inhibited by Q3 and Q2, while Q1 had no effect on the growth of this fungus. Growth of Penicillium expansum was only slightly inhibited by higher concentrations of sample Q3, while Q2 and Q1 had no effect. The inhibition of growth rates or their resistance toward chitooligosaccharides correlated with the absence or presence of chitinolytic enzymes in the culture media, respectively.}, language = {en} } @misc{OlsonDavidsonKliegletal.1984, author = {Olson, Richard K. and Davidson, Brian J. and Kliegl, Reinhold and Davies, Susan E.}, title = {Development of phonetic memory in disabled and normal readers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16888}, year = {1984}, abstract = {The development of phonetic codes in memory of 141 pairs of normal and disabled readers from 7.8 to 16.8 years of age was tested with a task adapted from L. S. Mark, D. Shankweiler, I. Y. Liberman, and C. A. Fowler (Memory \& Cognition, 1977, 5, 623-629) that measured false-positive errors in recognition memory for foil words which rhymed with words in the memory list versus foil words that did not rhyme. Our younger subjects replicated Mark et al., showing a larger difference between rhyming and nonrhyming false-positive errors for the normal readers. The older disabled readers' phonetic effect was comparable to that of the younger normal readers, suggesting a developmental lag in their use of phonetic coding in memory. Surprisingly, the normal readers' phonetic effect declined with age in the recognition task, but they maintained a significant advantage across age in the auditory WISC-R digit span recall test, and a test of phonological nonword decoding. The normals' decline with age in rhyming confusion may be due to an increase in the precision of their phonetic codes.}, language = {en} } @misc{OlsonKlieglDavidson1983, author = {Olson, Richard K. and Kliegl, Reinhold and Davidson, Brian J.}, title = {Dyslexic and normal readers' eye movements}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41071}, year = {1983}, abstract = {Dyslexic and normal readers' eye movements were compared while tracking a moving fixation point and in reading. Contrary to previous reports, the dyslexic and normal readers did not differ in their number of saccades, percentage of regressions, or stability of fixations in the tracking task. Thus, defective oculomotor control was not associated with or a causal factor in dyslexia, and the dyslexics' abnormal eye movements in reading must be related to differences in higher cognitive processes. However, individual differences in oculmotor efficiency, independent of reading ability, were found within both the dyslexic and normal groups, and these differences were correlated in reading and tracking tasks.}, language = {en} } @misc{OlsonKlieglDavidson1983, author = {Olson, Richard K. and Kliegl, Reinhold and Davidson, Brian J.}, title = {Eye Movements in Reading Disability}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-39880}, year = {1983}, abstract = {Contents: I. Introduction II. Word Coding Processes A. Word Recognition B. Orthographic Coding C. Phonological Coding III. Eye Monitor and Reading Task IV. Group Differences V. Dimensions of Individual Differences A. Regressive Fixation Index and Word Recognition B. Regressive Fixation Index and IQ C. Regressive Fixation Index and Saccade Length D. Regressive Fixation Index and Relative Phonological Skill VI. Multiple Regression Models of Individual Differences A. Disabled Readers in the Aloud Condition B. Disabled Readers in the Silent Condition C. Normal Readers in Silent and Aloud Conditions VII. Conclusions}, language = {en} } @misc{OlsonKlieglDavidsonetal.1985, author = {Olson, Richard K. and Kliegl, Reinhold and Davidson, Brian J. and Foltz, Gregory}, title = {Individual and developmental differences in reading disability}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-39916}, year = {1985}, abstract = {I. Introduction A. Theoretical Framework and Selection of Tests B. Related Studies of Reading Disability Subtypes C. Overview of Specific Questions and Article Outline II. Selection criteria nd performance on standardized measures III. Group differences between disabled and normal readers A. Phonetic Memory B. Picture-Naming Speed and Automatic Responses to Print C. Phonological and Orthographic Skill D. Easy Regular and Exception Word Reading E. Difficult Regular and Exception Words IV. Individual diferences in reading disability A. Phonological Skill, Orthographic Skill, and the Regularity Effect B. Phonological Skill, Orthographic Skill, and Spelling Errors V. Eye movement reading style A. The "Plodder-Explorer" Dimension of Eye Movement Reading Style B. Eye Movements, Coding Skills, and Spelling Ratings C. Verbal Intelligence and the Plodder-Explorer Dimension D. Eye Movements in a Nonreading Task and the "Visual-Spatial" Subtype VI. Distribution and etiology of reading disabilities A. Distribution Issues B. Etiology of Reading Disabilities VII. Summary and new directions in research}, language = {en} } @misc{OngKliegl2008, author = {Ong, James Kwan Yau and Kliegl, Reinhold}, title = {Conditional co-occurrence probability acts like frequency in predicting fixation durations}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-56771}, year = {2008}, abstract = {The predictability of an upcoming word has been found to be a useful predictor in eye movement research, but is expensive to collect and subjective in nature. It would be desirable to have other predictors that are easier to collect and objective in nature if these predictors were capable of capturing the information stored in predictability. This paper contributes to this discussion by testing a possible predictor: conditional co-occurrence probability. This measure is a simple statistical representation of the relatedness of the current word to its context, based only on word co-occurrence patterns in data taken from the Internet. In the regression analyses, conditional co-occurrence probability acts like lexical frequency in predicting fixation durations, and its addition does not greatly improve the model fits. We conclude that readers do not seem to use the information contained within conditional co-occurrence probability during reading for meaning, and that similar simple measures of semantic relatedness are unlikely to be able to replace predictability as a predictor for fixation durations. Keywords: Co-occurrence probability, Cloze predictability, frequency, eye movement, fixation duration.}, language = {en} } @misc{OttvandeVijverHoehle2006, author = {Ott, Susan and van de Vijver, Ruben and H{\"o}hle, Barbara}, title = {The effect of phonotactic constraints in German-speaking children with delayed phonological acquisition : evidence from production of word-initial consonant clusters}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16316}, year = {2006}, abstract = {In this study the effect of phonotactic constraints concerning word-initial consonant clusters in children with delayed phonological acquisition was explored. Twelve German-speaking children took part (mean age 5;1). The spontaneous speech of all children was characterized by the regular appearance of the error patterns fronting, e.g., Kuh (cow) → /tu:/, or stopping, e.g., Schaf (sheep) → /ta:f/, which were inappropriate for their chronological age. The children were asked to produce words (picture naming task, word repetition task) with initial consonant clusters, in which the application of the error patterns would violate phonotactic sequence constraints. For instance, if fronting would apply in /kl-/, e.g., Kleid (dress), it would be realized as the phontactically illegal consonant cluster /tl-/. The results indicate that phonotactic constraints affect word production in children with delayed phonological developments. Surprisingly, we found that children with fronting produced the critical consonants correctly significantly more often in word-initial consonant clusters than in words in which they appeared as singleton onsets. In addition, the results provide evidence for a similar developmental trajectory of acquisition in children with typical development and in children with delayed phonological acquisition. Keywords: Children with delayed phonological acquisition, phonotactic constraints, word-initial consonant clusters, fronting, stopping.}, language = {en} } @misc{PedersenJohannsen2004, author = {Pedersen, Karin Hilmer and Johannsen, Lars}, title = {The real challenge for change : public administration in new EU member states}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-46718}, year = {2004}, abstract = {Executive responsibility for EU policies is by tradition delegated to the member states and their internal administrative bodies. It is therefore of outmost importance that the new Central and East European members have the capacity to administer the acquis communitaire once they are full members of the EU. Based on a survey among current and former top-level decision-makers (ministers), this article argues that although there are significant implementation problems, efficiency gains can be made through administrative reform and not the least education aimed at changing the worldview and knowledge of the individual civil servant. However, there seem to be significant differences in how these countries tackle implementation problems and administrative reform.}, language = {en} } @misc{Peter1980, author = {Peter, Martin G.}, title = {Products of in vitro oxidation of N-acetyldopamine as possible components in the sclerotization of insect cuticle}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16759}, year = {1980}, abstract = {[1-14C]-N-Acetyldopamine (NADA) was oxidized in the presence of methyl [3-3H]-β-alanate with mushroom tyrosinase. The complex mixture of reaction products was partly resolved by chromatographic procedures and analyzed by spectroscopic methods. Methyl-β-alanate is incorporated to only a small extent into oxidation products of NADA which inter alia are presumed to be oligomeric hydroxyquinones. After oxidation of [1-14C, 2-3H]-NADA with preparations from tanning Manduca sexta pupal cuticle, N-acetylnoradrenalin was identified as one of the products. Binding of radioactivity to melanin-like material was also observed. These results suggest that oxidation products different from those formulated usually for the crosslinkages between protein amino groups and N-acetyldopaquinone are deposited in darkly brown coloured insect cuticles during sclerotization.}, language = {en} } @misc{PeterAndersenHartmannetal.1992, author = {Peter, Martin G. and Andersen, Svend Olav and Hartmann, Rudolf and Miessner, Merle and Roepstorff, Peter}, title = {Catecholamine-protein conjugates : isolation of 4-phenylphenoxazin-2-ones from oxidative coupling of N-acetyldopamine with alipathic amino acids}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17571}, year = {1992}, abstract = {4-Phenylphenoxazinones were isolated after biomimetic oxidation, using diphenoloxidases of insect cuticle, mushroom tyrosinase, or after autoxidation of N-acetyldopamine (Image ) in the presence of β-alanine, β-alanine methyl ester or N-acetyl-L-lysine. They are formed presumably by addition of 2-aminoalkyl-5-alkylphenols to the o-quinone of biphenyltetrol which, in turn, arises from oxidative coupling of. The structures of present the first examples for the assembly of reasonably stable intermediates in the rather complex process of chemical modifications of aliphatic amino acid residues by o-quinones.}, language = {en} } @misc{PeterFoerster1989, author = {Peter, Martin G. and F{\"o}rster, Hans}, title = {On the structure of Eumelanins : identification of constitutional patterns by solid-state NMR spectroscopy}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17027}, year = {1989}, abstract = {Aus dem Inhalt: Melanins are complex polyphenolic polymers. They are usually formed in nature by enzyme-catalyzed oxidative polymerization of o-diphenols. The deep black eumelanins, derived from Dopa 1 or dopamine 3, are distinguished from the yellow to brown phaeomelanins obtained from Dopa in the presence of cysteine. Characteristic of eumelanins are the indole units, which are formed from catecholamines by intramolecular addition of the amino groups to the oxidatively generated o-quinones. [...]}, language = {en} } @misc{PlathHermannSchroederetal.2010, author = {Plath, Martin and Hermann, Bernd and Schr{\"o}der, Christine and Riesch, R{\"u}diger and Tobler, Michael and Garc{\´i}a de Le{\´o}n, Francisco J. and Schlupp, Ingo and Tiedemann, Ralph}, title = {Locally adapted fish populations maintain small-scale genetic differentiation despite perturbation by a catastrophic flood event}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-48599}, year = {2010}, abstract = {Background: Local adaptation to divergent environmental conditions can promote population genetic differentiation even in the absence of geographic barriers and hence, lead to speciation. Perturbations by catastrophic events, however, can distort such parapatric ecological speciation processes. Here, we asked whether an exceptionally strong flood led to homogenization of gene pools among locally adapted populations of the Atlantic molly (Poecilia mexicana, Poeciliidae) in the Cueva del Azufre system in southern Mexico, where two strong environmental selection factors (darkness within caves and/or presence of toxic H2S in sulfidic springs) drive the diversification of P. mexicana. Nine nuclear microsatellites as well as heritable female life history traits (both as a proxy for quantitative genetics and for trait divergence) were used as markers to compare genetic differentiation, genetic diversity, and especially population mixing (immigration and emigration) before and after the flood. Results: Habitat type (i.e., non-sulfidic surface, sulfidic surface, or sulfidic cave), but not geographic distance was the major predictor of genetic differentiation. Before and after the flood, each habitat type harbored a genetically distinct population. Only a weak signal of individual dislocation among ecologically divergent habitat types was uncovered (with the exception of slightly increased dislocation from the Cueva del Azufre into the sulfidic creek, El Azufre). By contrast, several lines of evidence are indicative of increased flood-induced dislocation within the same habitat type, e.g., between different cave chambers of the Cueva del Azufre. Conclusions: The virtual absence of individual dislocation among ecologically different habitat types indicates strong natural selection against migrants. Thus, our current study exemplifies that ecological speciation in this and other systems, in which extreme environmental factors drive speciation, may be little affected by temporary perturbations, as adaptations to physico-chemical stressors may directly affect the survival probability in divergent habitat types.}, language = {en} } @misc{Priewe2011, author = {Priewe, Marc}, title = {Walter W. Woodward, Prospero´s America: John Winthrop, Jr., Alchemy, and the Creation of New England Culture, 1606-1676 / [rezensiert von] Marc Priewe}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93713}, pages = {199 -- 200}, year = {2011}, abstract = {Rezensiertes Werk: Walter W. Woodward: Prospero's America: John Winthrop, Jr., Alchemy, and the Creation of New England Culture, 1606-1676. Chapel Hill: University of North Carolina Press, 2010. Hb. 336pp. ISBN 978-0-8078-3301-8.}, language = {en} } @misc{PueschelChrist1994, author = {P{\"u}schel, Gerhard Paul and Christ, Bruno}, title = {Inhibition by PGE₂ of glucagon-induced increase in phosphoenolpyruvate carboxykinase mRNA and acceleration of mRNA degradation in cultured rat hepatocytes}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45792}, year = {1994}, abstract = {In cultured rat hepatocytes the key gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PCK) is known to be induced by glucagon via an elevation of cAMP. Prostaglandin E₂ has been shown to antagonize the glucagon-activated cAMP formation, glycogen phosphorylase activity and glucose output in hepatocytes. It was the purpose of the current investigation to study the potential of PGE₂ to inhibit the glucagon-induced expression of PCK on the level of mRNA and enzyme activity. PCK mRNA and enzyme activity were increased by 0.1 nM glucagon to a maximum after 2 h and 4 h, respectively. This increase was completely inhibited if 10 μM PGE2 was added concomitantly with glucagon. This inhibition by PGE₂ of glucagon-induced PCK activity was abolished by pertussis toxin treatment. When added at the maximum of PCK mRNA at 2 h, PGE₂ accelerated the decay of mRNA and reduced enzyme activity. This effect was not reversed by pertussis toxin treatment. Since in liver PGE₂ is derived from Kupffer cells, which play a key role in the local inflammatory response, the present data imply that during inflammation PGE₂ may reduce the hepatic gluconeogenic capacity via a Gᵢ-linked signal chain.}, language = {en} } @misc{PueschelHespelingOppermannetal.1993, author = {P{\"u}schel, Gerhard Paul and Hespeling, Ursula and Oppermann, Martin and Dieter, Peter}, title = {Increase in prostanoid formation in rat liver macrophages (Kupffer cells) by human anaphylatoxin C3a}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16716}, year = {1993}, abstract = {Human anaphylatoxin C3a increases glycogenolysis in perfused rat liver. This action is inhibited by prostanoid synthesis inhibitors and prostanoid antagonists. Because prostanoids but not anaphylatoxin C3a can increase glycogenolysis in hepatocytes, it has been proposed that prostanoid formation in nonparenchymal cells represents an important step in the C3a-dependent increase in hepatic glycogenolysis. This study shows that (a) human anaphylatoxin C3a (0.1 to 10 mug/ml) dose-dependently increased prostaglandin D2, thromboxane B, and prostaglandin F2alpha formation in rat liver macrophages (Kupffer cells); (b) the C3a-mediated increase in prostanoid formation was maximal after 2 min and showed tachyphylaxis; and (c) the C3a-elicited prostanoid formation could be inhibited specifically by preincubation of C3a with carboxypeptidase B to remove the essential C-terminal arginine or by preincubation of C3a with Fab fragments of a neutralizing monoclonal antibody. These data support the hypothesis that the C3a-dependent activation of hepatic glycogenolysis is mediated by way of a C3a-induced prostanoid production in Kupffer cells.}, language = {en} } @misc{PueschelJungermann1988, author = {P{\"u}schel, Gerhard Paul and Jungermann, Kurt}, title = {Activation of inositol phosphate formation by circulating noradrenaline but not by sympathetic nerve stimulation with a similar increase of glucose release in perfused rat liver}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45846}, year = {1988}, abstract = {In the isolated rat liver perfused in situ, stimulation of the nerve bundles around the hepatic artery and portal vein caused an increase of glucose and lactate output and a reduction of perfusion flow. These changes could be inhibited completely by α-receptor blockers. The possible involvement of inositol phosphates in the intracellular signal transmission was studied. 1. In cell-suspension experiments, which were performed as a positive control, noradrenaline caused an increase in glucose output and, in the presence of 10 mM LiCl, a dose-dependent and time-dependent increase of inositol mono, bis and trisphosphate. 2. In the perfused rat liver 1 μM noradrenaline caused an increase of glucose and lactate output and in the presence of 10 mM LiCl a time-dependent increase of inositol mono, bis and trisphosphate that was comparable to that observed in cell suspensions. 3. In the perfused rat liver stimulation of the nerve bundles around the portal vein and hepatic artery caused a similar increase in glucose and lactate output to that produced by noradrenaline, but in the presence of 10 mM LiCl there was a smaller increase of inositol monophosphate and no increase of inositol bis and trisphosphate. These findings are in line with the proposal that circulating noradrenaline reaches every hepatocyte, causing a clear overall increase of inositol phosphate formation and thus calcium release from the endoplasmic reticulum, while the hepatic nerves reach only a few cells causing there a small local change of inositol phosphate metabolism and thence a propagation of the signal via gap junctions.}, language = {en} } @misc{PueschelKirchnerSchroederetal.1993, author = {P{\"u}schel, Gerhard Paul and Kirchner, C. and Schr{\"o}der, A. and Jungermann, Kurt}, title = {Glycogenolytic and antiglycogenolytic prostaglandin E₂ actions in rat hepatocytes are mediated via different signalling pathways}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45853}, year = {1993}, abstract = {Prostaglandin E₂ has been reported both to stimulate glycogen-phosphorylase activity (glycogenolytic effect) and to inhibit the glucagon-stimulated glycogen-phosphorylase activity (antiglycogenolytic effect) in rat hepatocytes. It was the purpose of this study to resolve this apparent contradiction and to characterize the signalling pathways and receptor subtypes involved in the opposing prostaglandin E₂ actions. Prostaglandin E₂ (10 μM) increased glucose output, glycogen-phosphorylase activity and inositol trisphosphate formation in hepatocyte cell culture andor suspension. In the same systems, prostaglandin E₂ decreased the glucagon-stimulated (1 nM) glycogen-phosphorylase activity and cAMP formation. The signalling pathway leading to the glycogenolytic effect of PGE₂ was interrupted by incubation of the hepatocytes with 4P-phorbol 12-myristate 13-acetate (100 nM) for 10 min, while the antiglycogenolytic effect of prostaglandin E₂ was not attenuated. The signalling pathway leading to the antiglycogenolytic effect of prostaglandin E₂ was interrupted by an incubation of cultured hepatocytes with pertussis toxin (100 ng/ml) for 18 h, whereas the glycogenolytic effect of prostaglandin E₂ was enhanced. The EP₁/EP₃ prostaglandin-E₂-receptor-specific prostaglandin E₂ analogue Sulproston had a stronger glycogenolytic potency than the EP₃ prostaglandin-E₂-receptor-specific prostaglandin E₂ analogue Misoprostol. The antiglycogenolytic potency of both agonists was equal. It is concluded that the glycogenolytic and the antiglycogenolytic effects of prostaglandin E₂ are mediated via different signalling pathways in hepatocytes possibly involving EP₁ and EP₃ prostaglandin E₂ receptors, respectively.}, language = {en} } @misc{PueschelMentleinHeymann1982, author = {P{\"u}schel, Gerhard Paul and Mentlein, Rolf and Heymann, Eberhard}, title = {Isolation and characterization of Dipeptidyl Peptidase IV from human placenta}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45875}, year = {1982}, abstract = {Human placenta is surprisingly rich in post-proline dipeptidyl peptidase activity. Among various cell fractions, microsomes have the highest specific activity. A homogeneous enzyme preparation is obtained in a six-step purification procedure. The final preparation appears homogeneous upon dodecyl sulfate electrophoresis, but analytical isoelectric focussing reveals various active bands with isoelectric points in the range of pH 3 - 4. The enzyme is a glycoprotein containing about 30\% carbohydrate. Treatment with neuraminidase lowers the isoelectric points but does not reduce the heterogeneity of the band pattern. The subunit molecular weight is 120000 as estimated by dodecyl sulfate electrophoresis, whereas Mr of the native enzyme is > 200000, as can be concluded from gel filtration experiments. The purified dipeptidyl peptidase cleaves various synthetic and natural peptides, including substance P, kentsin, casomorphin and a synthetic renin inhibitor. In general, the specificity of the placenta peptidase is similar to that of post-proline dipeptidyl peptidase from other sources. Phenylalanylprolyl-P-naphthylamide (Km = 0.02 mM, I/ = 92 Ujmg) is the best substrate among various synthetic peptide derivatives. Only peptides with a free N-terminal amino group and proline, hydroxyproline, or alanine in position 2 of the N-terminal sequence are cieaved. However, X-Pro-Pro- . . . structures, e. g. as in bradykinin, are not attacked. 1 mM bis-(6nitrophenyI)phosphate or 1 mM diisopropylfluorophosphate completely inactivate the peptidase within 30 min at 30°C (pH 8). The peptidase is also completely inhibited by 1 mM Zn²⁺ and by other heavy metals.}, language = {en} } @misc{PueschelMiuraNeuschaeferRubeetal.1993, author = {P{\"u}schel, Gerhard Paul and Miura, Hisayuki and Neusch{\"a}fer-Rube, Frank and Jungermann, Kurt}, title = {Inhibition by the protein kinase C activator 4β-phorbol 12-myristate 13-acetate of the prostaglandin F₂α-mediated and noradrenaline-mediated but not glucagon-mediated activation of glycogenolysis in rat liver}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45889}, year = {1993}, abstract = {In perfused rat livers, infusion of prostaglandin F₂α (PGF₂α) or noradrenaline increased glucose and lactate output and reduced flow. Glucagon increased glucose output and decreased lactate output without influence on flow. Infusion of phorbol 13-myristate 14-acetate (PMA) for 20 min prior to these stimuli strongly inhibited the metabolic and hemodynamic effects of noradrenaline, reduced the metabolic actions of PGF₂α but did not alter the effects of glucagon. In isolated rat hepatocytes PGF₂α, noradrenaline and glucagon activated glycogen phosphorylase but only PGF₂α and noradrenaline increased intracellular inositol 1,4,5-1risphosphalc (InsP₃). The noradrenaline- or PGF₂α-elicited activation of glycogen phosphorylase and increase in InsP₃ were largely reduced after preincubation of the cells for 10 min with PMA, whereas the glucagon-mediated enzyme activation was not affected. In contra\t to PMA, the phorbol ester 4a-phorbol 13,14-didecanoate. which does not activate protein kinase C, did not attenuate the PGF₂α- and noradrenaline-elicited stimulation of glucose output, glycogen phosphorylase and InsP, formation. Stimulation of InsP₃ formation by AlF₄⁻, which activates phospholipase C independently of the receptor, was not attenuated by prior incubation with PMA. Plasma membranes purified from isolated hepatocytes had both a high-capacity, low-affinity and a low-capacity, high-affinity binding site for PGF₂α. The Kd of the high-capacity, low-affinity binding site was close to the concentration of PGF₂α that increased glycogen phosphorylase activity halfmaximally. Binding to the high-capacity, low-affinity binding site was enhanced by guanosine 5'- 0-(3-thio)triphosphate (GTP[S]). This high-capacity, low-affinity site might thus represent the receptor. The Bmax and Kd of the high-capacity site, as well as the enhancement by GTP[S] of PGF₂α binding to this site, remained unaffected by PMA pretreatment. It is concluded that, in hepatocytes, activation of protein kinase C by PMA interrupted the InsP₃-mediated signal pathway from PGF₂α via a PGF₂α receptor and phospholipase C to glycogen phosphorylase at a point distal of the receptor prior to phospholipase C.}, language = {en} } @misc{PueschelNathJungermann1987, author = {P{\"u}schel, Gerhard Paul and Nath, Annegret and Jungermann, Kurt}, title = {Increase of urate formation by stimulation of sympathetic hepatic nerves, circulating noradrenaline and glucagon inthe perfused rat liver}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16728}, year = {1987}, abstract = {In the isolated rat liver perfused in situ stimulation of the nerve bundles around the portal vein and the hepatic artery caused an increase of urate formation that was inhibited by the α1-blocker prazosine and the xanthine oxidase inhibitor allopurinol. Moreover, nerve stimulation increased glucose and lactate output and decreased perfusion flow. Infusion of noradrenaline had similar effects. Compared to nerve stimulation infusion of glucagon led to a less pronounced increase of urate formation and a twice as large increase in glucose output but a decrease in lactate release without affecting the flow rate. Insulin had no effect on any of the parameters studied.}, language = {en} } @misc{PueschelOppermannMuscholetal.1989, author = {P{\"u}schel, Gerhard Paul and Oppermann, Martin and Muschol, Waldemar and G{\"o}tze, Otto and Jungermann, Kurt}, title = {Increase of glucose and lactate output and decrease of flow by human anaphylatoxin C3a but not C5a in perfused rat liver}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16733}, year = {1989}, abstract = {The complement fragments C3a and C5a were purified from zymosan-activated human serum by column chromatographic procedures after the bulk of the proteins had been removed by acidic polyethylene glycol precipitation. In the isolated in situ perfused rat liver C3a increased glucose and lactate output and reduced flow. Its effects were enhanced in the presence of the carboxypeptidase inhibitor DL-mercaptomethyl-3-guanidinoethylthio-propanoic acid (MERGETPA) and abolished by preincubation of the anaphylatoxin with carboxypeptidase B or with Fab fragments of an anti-C3a monoclonal antibody. The C3a effects were partially inhibited by the thromboxane antagonist BM13505. C5a had no effect. It is concluded that locally but not systemically produced C3a may play an important role in the regulation of local metabolism and hemodynamics during inflammatory processes in the liver.}, language = {en} } @misc{PueschelOppermannNeuschaeferRubeetal.1991, author = {P{\"u}schel, Gerhard Paul and Oppermann, Martin and Neusch{\"a}fer-Rube, Frank and G{\"o}tze, Otto and Jungermann, Kurt}, title = {Differential effects of human anaphylatoxin C3a on glucose output and flow in rat liver during orthograde and retrograde perfusion : the periportal scavenger cell hypothesis}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16747}, year = {1991}, abstract = {1) During orthograde perfusion of rat liver human anaphylatoxin C3a caused an increase in glucose and lactate output and reduction of flow. These effects could be enhanced nearly twofold by co-infusion of the carboxypeptidase inhibitor MERGETPA, which reduced inactivation of C3a to C3adesArg. 2) During retrograde perfusion C3a caused a two- to threefold larger increase in glucose and lactate output and reduction of flow than in orthograde perfusions. These actions tended to be slightly enhanced by MERGETPA. 3) The elimination of C3a plus C3adesArg immunoreactivity during a single liver passage was around 67\%, irrespective of the perfusion direction and the presence of the carboxypeptidase inhibitor MERGETPA; however, less C3adesArg and more intact C3a appeared in the perfusate in the presence of MERGETPA in orthograde and retrogade perfusions It is concluded that rat liver inactivated human anaphylatoxin C3a by conversion to C3adesArg and moreover eliminated it by an additional process. The inactivation to C3adesArg seemed to be located predominantly in the proximal periportal region of the liver sinusoid, since C3a was less effective in orthograde perfusions, when C3a first passed the proximal periportal region before reaching the predominant mass of parenchyma as its site of action, than in retrograde perfusions, when it first passed the perivenous area. These data may be evidence for a periportal scavenger mechanism, by which the liver protects itself from systemically released mediators of inflammation that interfere with the local regulation of liver metabolism and hemodynamics.}, language = {en} } @misc{ReichLoehmannsroebenSchael2003, author = {Reich, Oliver and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Schael, Frank}, title = {Optical sensing with photon density waves: investigation of model media}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13147}, year = {2003}, abstract = {Investigations with frequency domain photon density waves allow elucidation of absorption and scattering properties of turbid media. The temporal and spatial propagation of intensity modulated light with frequencies up to more than 1 GHz can be described by the P1 approximation to the Boltzmann transport equation. In this study, we establish requirements for the appropriate choice of turbid model media and characterize mixtures of isosulfan blue as absorber and polystyrene beads as scatterer. For these model media, the independent determination of absorption and reduced scattering coefficients over large absorber and scatterer concentration ranges is demonstrated with a frequency domain photon density wave spectrometer employing intensity and phase measurements at various modulation frequencies.}, language = {en} } @misc{Reich1995, author = {Reich, Sebastian}, title = {Smoothed dynamics of highly oscillatory Hamiltonian systems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15639}, year = {1995}, abstract = {We consider the numerical treatment of Hamiltonian systems that contain a potential which grows large when the system deviates from the equilibrium value of the potential. Such systems arise, e.g., in molecular dynamics simulations and the spatial discretization of Hamiltonian partial differential equations. Since the presence of highly oscillatory terms in the solutions forces any explicit integrator to use very small step size, the numerical integration of such systems provides a challenging task. It has been suggested before to replace the strong potential by a holonomic constraint that forces the solutions to stay at the equilibrium value of the potential. This approach has, e.g., been successfully applied to the bond stretching in molecular dynamics simulations. In other cases, such as the bond-angle bending, this methods fails due to the introduced rigidity. Here we give a careful analysis of the analytical problem by means of a smoothing operator. This will lead us to the notion of the smoothed dynamics of a highly oscillatory Hamiltonian system. Based on our analysis, we suggest a new constrained formulation that maintains the flexibility of the system while at the same time suppressing the high-frequency components in the solutions and thus allowing for larger time steps. The new constrained formulation is Hamiltonian and can be discretized by the well-known SHAKE method.}, language = {en} } @misc{Reich1992, author = {Reich, Sebastian}, title = {Differential-algebraic equations and applications in circuit theory}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-46646}, year = {1992}, abstract = {Technical and physical systems, especially electronic circuits, are frequently modeled as a system of differential and nonlinear implicit equations. In the literature such systems of equations are called differentialalgebraic equations (DAEs). It turns out that the numerical and analytical properties of a DAE depend on an integer called the index of the problem. For example, the well-known BDF method of Gear can be applied, in general, to a DAE only if the index does not exceed one. In this paper we give a geometric interpretation of higherindex DAEs and indicate problems arising in connection with such DAEs by means of several examples.}, language = {en} } @misc{Reich1990, author = {Reich, Sebastian}, title = {On a geometrical interpretation of differential-algebraic equations}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-46683}, year = {1990}, abstract = {The subject of this paper is the relation of differential-algebraic equations (DAEs) to vector fields on manifolds. For that reason, we introduce the notion of a regular DAE as a DAE to which a vector field uniquely corresponds. Furthermore, a technique is described which yields a family of manifolds for a given DAE. This socalled family of constraint manifolds allows in turn the formulation of sufficient conditions for the regularity of a DAE. and the definition of the index of a regular DAE. We also state a method for the reduction of higher-index DAEs to lowsr-index ones that can be solved without introducing additional constants of integration. Finally, the notion of realizability of a given vector field by a regular DAE is introduced, and it is shown that any vector field can be realized by a regular DAE. Throughout this paper the problem of path-tracing is discussed as an illustration of the mathematical phenomena.}, language = {en} } @misc{Reich1994, author = {Reich, Sebastian}, title = {Momentum conserving symplectic integrators}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-16824}, year = {1994}, abstract = {In this paper, we show that symplectic partitioned Runge-Kutta methods conserve momentum maps corresponding to linear symmetry groups acting on the phase space of Hamiltonian differential equations by extended point transformation. We also generalize this result to constrained systems and show how this conservation property relates to the symplectic integration of Lie-Poisson systems on certain submanifolds of the general matrix group GL(n).}, language = {en} } @misc{Reich1995, author = {Reich, Sebastian}, title = {On the local qualitative behavior of differential-algebraic equations}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-46739}, year = {1995}, abstract = {A theoretical famework for the investigation of the qualitative behavior of differential-algebraic equations (DAEs) near an equilibrium point is established. The key notion of our approach is the notion of regularity. A DAE is called regular locally around an equilibrium point if there is a unique vector field such that the solutions of the DAE and the vector field are in one-to-one correspondence in a neighborhood of this equili Drium point. Sufficient conditions for the regularity of an equilibrium point are stated. This in turn allows us to translate several local results, as formulated for vector fields, to DAEs that are regular locally around a g: ven equilibrium point (e.g. Local Stable and Unstable Manifold Theorem, Hopf theorem). It is important that ihese theorems are stated in terms of the given problem and not in terms of the corresponding vector field.}, language = {en} } @misc{Reich1991, author = {Reich, Sebastian}, title = {On an existence and uniqueness theory for nonlinear differential-algebraic equations}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-46706}, year = {1991}, abstract = {An existence and uniqueness theory is developed for general nonlinear and nonautonomous differential-algebraic equations (DAEs) by exploiting their underlying differential-geometric structure. A DAE is called regular if there is a unique nonautonomous vector field such that the solutions of the DAE and the solutions of the vector field are in one-to-one correspondence. Sufficient conditions for regularity of a DAE are derived in terms of constrained manifolds. Based on this differential-geometric characterization, existence and uniqueness results are stated for regular DAEs. Furthermore, our not ons are compared with techniques frequently used in the literature such as index and solvability. The results are illustrated in detail by means of a simple circuit example.}, language = {en} } @misc{RisseKliegl2011, author = {Risse, Sarah and Kliegl, Reinhold}, title = {Adult age differences in the perceptual span during reading}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-56935}, year = {2011}, abstract = {Following up on research suggesting an age-related reduction in the rightward extent of the perceptual span during reading (Rayner, Castelhano, \& Yang, 2009), we compared old and young adults in an N+2-boundary paradigm in which a nonword preview of word N+2 or word N+2 itself is replaced by the target word once the eyes cross an invisible boundary located after word N. The intermediate word N+1 was always three letters long. Gaze durations on word N+2 were significantly shorter for identical than nonword N+2 preview both for young and for old adults with no significant difference in this preview benefit. Young adults, however, did modulate their gaze duration on word N more strongly than old adults in response to the difficulty of the parafoveal word N+1. Taken together, the results suggest a dissociation of preview benefit and parafoveal-on-foveal effect. Results are discussed in terms of age-related decline in resilience towards distributed processing while simultaneously preserving the ability to integrate parafoveal information into foveal processing. As such, the present results relate to proposals of regulatory compensation strategies older adults use to secure an overall reading speed very similar to that of young adults.}, language = {en} } @misc{RolfsEngbertKliegl2005, author = {Rolfs, Martin and Engbert, Ralf and Kliegl, Reinhold}, title = {Crossmodal coupling of oculomotor controland spatial attention in vision and audition}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-56804}, year = {2005}, abstract = {Fixational eye movements occur involuntarily during visual fixation of stationary scenes. The fastest components of these miniature eye movements are microsaccades, which can be observed about once per second. Recent studies demonstrated that microsaccades are linked to covert shifts of visual attention [e.g., Engbert \& Kliegl (2003), Vision Res 43:1035-1045]. Here,we generalized this finding in two ways. First, we used peripheral cues, rather than the centrally presented cues of earlier studies. Second, we spatially cued attention in vision and audition to visual and auditory targets. An analysis of microsaccade responses revealed an equivalent impact of visual and auditory cues on microsaccade-rate signature (i.e., an initial inhibition followed by an overshoot and a final return to the pre-cue baseline rate). With visual cues or visual targets,microsaccades were briefly aligned with cue direction and then opposite to cue direction during the overshoot epoch, probably as a result of an inhibition of an automatic saccade to the peripheral cue. With left auditory cues and auditory targets microsaccades oriented in cue direction. Thus, microsaccades can be used to study crossmodal integration of sensory information and to map the time course of saccade preparation during covert shifts of visual and auditory attention.}, language = {en} } @misc{RolfsKlieglEngbert2004, author = {Rolfs, Martin and Kliegl, Reinhold and Engbert, Ralf}, title = {Microsaccade orientation supports attentional enhancement opposite to a peripheral cue: Commentary on Tse, Sheinberg, and Logothetis}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57081}, year = {2004}, language = {en} } @misc{RolfsLaubrockKliegl2006, author = {Rolfs, Martin and Laubrock, Jochen and Kliegl, Reinhold}, title = {Shortening and Prolongation of Saccade Latencies Following Microsaccades}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57012}, year = {2006}, abstract = {When the eyes fixate at a point in a visual scene, small saccades rapidly shift the image on the retina. The effect of these microsaccades on the latency of subsequent large-scale saccades may be twofold. First, microsaccades are associated with an enhancement of visual perception. Their occurrence during saccade target perception should, thus, decrease saccade latencies. On the other hand, microsaccades likely indicate activity in fixation-related oculomotor neurons. These represent competitors to saccade-related cells in the interplay of gaze holding and shifting. Consequently, an increase in saccade latencies after microsaccades would be expected. Here, we present evidence for both aspects of microsaccadic impact on saccade latency. In a delayed response task, participants made saccades to visible or memorized targets. First, microsaccade occurrence up to 50 ms before target disappearance correlated with 18 ms (or 8\%) faster saccades to memorized targets. Second, if microsaccades occurred shortly (i.e., < 150 ms) before a saccade was required, saccadic reaction times in visual and memory trials were increased by about 40 ms (or 16\%). Hence, microsaccades can have opposite consequences for saccade latencies, pointing at a differential role of these fixational eye movements in preparation of motor programs.}, language = {en} } @misc{RozanskiKremerKoeberleetal.1995, author = {Rozanski, Stanislaw A. and Kremer, Friedrich and K{\"o}berle, Peter and Laschewsky, Andr{\´e}}, title = {Relaxation and charge transport in mixtures of zwitterionic polymers and inorganic salts}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17438}, year = {1995}, abstract = {Dielectric spectroscopy is employed to analyze the molecular dynamics and the charge transport in mixtures of zwitterionic polymers of the type poly{3 [N(-methacryloyloxyalkyl)] N, [N-dimethylammonio propanesulfonate] with sodium iodide in the frequency range of 10²Hz-10(up)7 Hz and in the temperature range of 110 K-400 K. The amount of inorganic salt added varies from 0-200 mol-\% relative to the number of zwitterionic groups present in the polymer, contributing strongly to the conductivity. One relaxation process is observed whose relaxation rate depends strongly on the length of the aliphatic spacer between the polymethacrylate main chain and the zwitterionic group. Exhibiting an Arrhenius-like temperature depence with activation energy EA = 47 KJ/mol, this relaxation process is assigned to fluctuation of the quaternary ammonium groups in the side chains. At higher temperatures, the dielectric properties and the conductivity are primarily dominated by the mobile inorganic ions: conductivity strongly depends on the salt concentration, showing a pronounced electrode polarization effect. The frequency and salt concentration, dependences of the conductivity can be quantitatively described as hopping of charge carriers being subject to spatially randomly varying energy barriers. For the low-frequency regime and for the critical frequency marking the onset of the conductivity's dispersion, the Barton-Nakajima-Namikawa (BNN) relationship is fulfilled.}, language = {en} } @misc{Sanner2005, author = {Sanner, Helge}, title = {Imperfect goods and labor markets, and the union wage gap}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6511}, year = {2005}, abstract = {Existing theoretical literature fails to explain satisfactorily the differences between the pay of workers that are covered by collective agreements and others who are not. This study aims at providing a model framework which is amenable for an analysis of this issue. Our general-equilibrium approach integrates a dual labor market and a two-sector product market. The results suggest that the so-called 'union wage gap' is largely determined by the degree of centralization of the bargains, and, to a somewhat lesser extent, by the expenditure share of the unionized sector's goods.}, subject = {Verhandlungstheorie}, language = {en} } @misc{Schiefele1992, author = {Schiefele, Ulrich}, title = {Topic interest and levels of text comprehension}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33696}, year = {1992}, language = {en} } @misc{Schiefele1987, author = {Schiefele, Ulrich}, title = {The importance of motivational factors for the acquisition and representation of knowledge}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33421}, year = {1987}, abstract = {Motivational conditions have been thus far largely neglected by contemporary theoretical approaches in knowledge psychology. The present article attempts to demonstrate the necessity for the greater integration of both. Suggestions are made regarding the choice and conceptualization of relevant motivational factors. Two possible groups of factors can be distinguished: (1) motivational factors of personality, and (2) motivational effects of action. Available theoretical approaches (e.g., the "levels of processing" approach) and examples are used to clarify the potential effects of these factors on the acquisition and representation of knowledge. Finally, a review is made of empirical studies allowing confirmatory allegations about the posited relationships between motivational factors and processes related to knowledge. This review reveals substantial research deficits on this topic.}, language = {en} } @misc{Schiefele1991, author = {Schiefele, Ulrich}, title = {Interest, learning, and motivation}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33536}, year = {1991}, abstract = {Recent research related to the concept of interest is reviewed. It is argued that current constructs of motivation fail to include crucial aspects of the meaning of interest emphasized by classical American and German educational theorists. In contrast with many contemporary concepts (e.g., intrinsic learning orientation), interest is defined as a content-specific motivational characteristic composed of intrinsic feeling-related and value-related valences. Results from a number of studies are presented that indicate the importance of interest for the depth of text comprehension, the use of learning strategies, and the quality of the emotional experience while learning. The implications of these results and possible directions for future research are discussed.}, language = {en} } @misc{Schiefele1990, author = {Schiefele, Ulrich}, title = {The influence of topic interest, prior knowledge, and cognitive capabilities on text comprehension}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33472}, year = {1990}, abstract = {The present study investigated the influence of topic interest on the comprehension of texts. The primary goals of the study were as follows: (1) to formulate a new definition of the concept "topic interest", (2) to control for cognitive capabilities (intelligence, short-term memory) and prior knowledge, and(3) to assess different levels of comprehension. A total of 53 male students, majoring in computer science, took part in the study. Subjects were presented with a text on "Psychology of Emotion". Prior to reading the text, they were asked to indicate their level of interest in the topic. After reading the text, subjects were given a test of comprehension involving open-ended questions. The questions were designed to represent different levels of comprehension. The results show that the effect of topic interest on text comprehension is especially pronounced when a deeper level of understanding is required. Surprisingly, prior knowledge had no effect on the level of comprehension. Verbal intelligence, on the other hand, showed a clear effect on comprehension, especially in answering questions of simple knowledge. The effects of interest and verbal intelligence could be shown to be independent of one another.}, language = {en} } @misc{SchmaelzlinDongenKlimantetal.2005, author = {Schm{\"a}lzlin, Elmar and Dongen, Joost T. van and Klimant, Ingo and Marmod{\´e}e, Bettina and Steup, Martin and Fishahn, Joachim and Geigenberger, Peter and L{\"o}hmannsr{\"o}ben, Hans-Gerd}, title = {An optical multifrequency phase-modulation method using microbeads for measuring intracellular oxygen concentrations in plants}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12232}, year = {2005}, abstract = {A technique has been developed to measure absolute intracellular oxygen concentrations in green plants. Oxygen-sensitive phosphorescent microbeads were injected into the cells and an optical multifrequency phase-modulation technique was used to discriminate the sensor signal from the strong autofluorescence of the plant tissue. The method was established using photosynthesis-competent cells of the giant algae Chara corallina L., and was validated by application to various cell types of other plant species.}, language = {en} } @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} } @misc{SchulerLipmanSteinbachetal.2005, author = {Schuler, Benjamin and Lipman, Everett A. and Steinbach, Peter J. and Kumke, Michael Uwe and Eaton, William A.}, title = {Polyproline and the "spectroscopic ruler" revisited with single-molecule fluorescence}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12229}, year = {2005}, abstract = {To determine whether F{\"o}rster resonance energy transfer (FRET) measurements can provide quantitative distance information in single-molecule fluorescence experiments on polypeptides, we measured FRET efficiency distributions for donor and acceptor dyes attached to the ends of freely diffusing polyproline molecules of various lengths. The observed mean FRET efficiencies agree with those determined from ensemble lifetime measurements but differ considerably from the values expected from F{\"o}rster theory, with polyproline treated as a rigid rod. At donor-acceptor distances much less than the F{\"o}rster radius R0, the observed efficiencies are lower than predicted, whereas at distances comparable to and greater than R0, they are much higher. Two possible contributions to the former are incomplete orientational averaging during the donor lifetime and, because of the large size of the dyes, breakdown of the point-dipole approximation assumed in F{\"o}rster theory. End-to-end distance distributions and correlation times obtained from Langevin molecular dynamics simulations suggest that the differences for the longer polyproline peptides can be explained by chain bending, which considerably shortens the donor-acceptor distances.}, language = {en} } @misc{SchaeferBungNest2008, author = {Sch{\"a}fer-Bung, Boris and Nest, Mathias}, title = {Correlated dynamics of electrons with reduced two-electron density matrices}, issn = {1866-8372}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41774}, year = {2008}, abstract = {We present an approach to the correlated dynamics of many-electron systems. We show, that the twoelectron reduced density matrix (2RDM) can provide a suitable description of the real time evolution of a system. To achieve this, the hierarchy of equations of motion must be truncated in a practical way. Also, the computational effort, given that the 2RDM is represented by products of two-electron determinants, is discussed, and numerical model calculations are presented.}, language = {en} } @misc{Selting1992, author = {Selting, Margret}, title = {Prosody in conversational questions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-36635}, year = {1992}, abstract = {My analysis of question-word questions in conversational question-answer sequences results in the decomposition of the conversational question into three systems of constitutive cues, which signal and contextualize the particular activity type in conversational interaction: (1) syntactic structure, (2) semantic relation to prior turn, and (3) prosody. These components are used and combined by interlocutors to distinguish between different activity types which (4) sequentially implicate different types of answers by the recipient in the next turn. Prosody is only one cooccurring cue, but in some cases it is the only distinctive one. It is shown that prosody, and in particular intonation, cannot be determined or even systematically related to syntactic sentence structure type or other sentence-grammatical principles, as most former and current theories of intonation postulate. Instead, prosody is an independent, autonomous signalling system, which is used as a contextualization device for the constitution of interactively relevant activity types in conversation.}, language = {en} } @misc{Selting1985, author = {Selting, Margret}, title = {Levels of style-shifting : exemplified in the interaction strategies of a moderator in a listener participation programme}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41273}, year = {1985}, abstract = {This paper investigates speech styles and style-shifting in the speech of the moderator of a German radio participation programme. Style-shifting is shown to affect several distinct linguistic levels: phonetic, morphophonemic, syntactic, and lexical. The functions of style-shifting are related both to the discourse context and the broader institutional context. Relying on listeners' co-occurrence expectations with respect to language use in contexts and exploiting listeners' evaluations of processes of speech convergence and divergence, the moderator uses stereotypic markers at different style levels in locally strategic functions in discourse. On the one hand, thematic development is controlled by reinforcing obligations on the addressee. On the other hand, global social reciprocity patterns are constituted and secured. Patterns of reciprocity vary with different types of addressees. The conversational analysis of language variation shows that variation is not only a quantitative correlate of regional, social and contextual parameters as predominantly conceived of in sociolinguistics. Language variation is furthermore used as a means to signal social and interactive meaning in conversations.}, language = {en} } @misc{Selting1994, author = {Selting, Margret}, title = {Question intonation revisited : the intonation of conversational questions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-43179}, year = {1994}, abstract = {Content: 1. Introduction 2. Aim and approach of the present analysis 3. Non-restrictive 'open' conversational questions 4. More restrictive "narrower" questions 5. "Deviant cases" 6. Conclusions}, language = {en} } @misc{Selting1989, author = {Selting, Margret}, title = {Speech style in conversation as an interactive achievement}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-43189}, year = {1989}, abstract = {Content: 1. Introduction 2. The notion of speech style: from a dependent variable to contextualization cue 3. Speech styles in conversation from a German Sozialamt 3.1 Extracts from conversation 3.2 Speech style constituting cues 3.3 Choice and alternation of speech styles in conversation 4. Summary and conclusions}, language = {en} } @misc{Selting1987, author = {Selting, Margret}, title = {Descriptive categories for the auditive analysis of intonation in conversation}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41986}, year = {1987}, abstract = {A system of descriptive categories for the notation and analysis of intonation in natural conversation is presented and discussed in relation to other systems currently suggested for incorporation in discourse analysis, The categories are based on purely auditive criteria. They differ from e.g. tonetic approaches by relying more on transcribers' and analysts' perception of the form and internal cohesiveness of contours, especially with respect to rhythmicality and/or pitch contour (gestalt). Intonation is conceived of as a relational phenomenon; the role of intonation in conversational utterances can only be analyzed by considering its co-occurrence with other properties of utterances like syntactic, semantic and discourse organizational structures and devices. In general, intonation is viewed as one signalling system contributing to the contextualization of utterances in their conversational context. A broad functional differentiation between different types of intonation categories seems plausible: Local categories like accents might fulfill mainly semantic functions, while global categories like different contour types might fulfill primarily functions with respect to the interactive coordination of activities in conversation.}, language = {en} } @misc{Selting1988, author = {Selting, Margret}, title = {The role of intonation in the organization of repair and problem handling sequences in conversation}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41992}, year = {1988}, abstract = {Transcripts of repair and/or problem handling sequences from natural conversations are presented and analyzed with special reference to the role of intonation in the interactive organization of these sequences. It is shown that (a) in the initiation of so-called repair or local problem handling sequences, intonation is used as a type-distinctive device, and (b) in the handling of a global problem handling sequence, intonation is systematically used as a means to constitute and control participant cooperation. In general, intonation is analyzed as one contextualization cue cooccurring with specific syntactic, semantic and discourse organizational devices to signal the status of an utterance in conversational context. It is hypothesized that especially in the global problem handling sequence, different categories of intonation, i.e. different accent and contour types, are systematically used to signal and control participants' interactive problem handling in different, indexically relevant ways simultaneously.}, language = {en} } @misc{Selting1992, author = {Selting, Margret}, title = {Intonation as a contextualization device : case studies on the role of prosody, especially intonation, in contextualizing story telling in conversation}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41903}, year = {1992}, abstract = {Content: 1. Introduction 2. Premisses and descriptive categories 3. A first example 4. A second example 4.1. The internal structure of the story 4.2. The embedding of the story into the surrounding conversation 4.3. Some other relations within the sequence 5. Conclusions}, language = {en} } @misc{Selting1994, author = {Selting, Margret}, title = {Emphatic speech style : with special focus on the prosodic signalling of heightened emotive involvement in conservation}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-37933}, year = {1994}, abstract = {After a review of previous work on the prosody of emotional involvement, data extracts from natural conversations are analyzed in order to argue for the constitution of an 'emphatic (speech) style', which linguistic devices are used to signal heightened emotive involvement. Participants use prosodic cues, in co-occurrence with syntactic and lexical cues, to contextualize turn-constructional units as 'emphatic'. Only realizations of prosodic categories that are marked in relation to surrounding uses of these categories have the power to contextualize units as displaying 'more-than-normal involvement'. In the appropriate context, and in cooccurrence with syntactic and lexical cues and sequential position, the context-sensitive interpretation of this involvement is 'emphasis'. Prosodic marking is used in addition to various unmarked cues that signal and constitute different activity types in conversation. Emphatic style highlights and reinforms particular conversational activities, and makes certain types of recipient responses locally relevant. In particular, switches from non-emphatic to emphatic style are used to contextualize 'peaks of involvement' or 'climaxes' in story-telling. These are shown in the paper to be 'staged' by speakers and treated by recipients as marked activities calling for displays of alignment with respect to the matter at hand. Signals of emphasis are deployable as techniques for locally organizing demonstrations of shared understanding and participant reciprocity in conversational interaction.}, language = {en} } @misc{SimonCabreraKliegl1993, author = {Simon, Tony and Cabrera, Angel and Kliegl, Reinhold}, title = {A new approach to the study of subitizing as distinct enumeration processing}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41083}, year = {1993}, abstract = {This paper presents a new methodology for examining the phenomenon of subitizing. Subjects were presented with a standard numerosity-detection task but for a range of presentation times to allow Task-Accuracy Functions to be computed for individual subjects. The data appear to show a continuous change in processing for numerosities from 2 to 5 when the data are aggregated across subjects. At the level of individual subjects, there appear to be qualitative shifts in enumeration processing after 3 or 4 objects. The approach used in this experiment may be used to test the claim that subitizing is a distinct enumeration process that can be used for small numbers of objects.}, language = {en} } @misc{SixKrahe1984, author = {Six, Bernd and Krah{\´e}, Barbara}, title = {Implicit psychologists' estimates of attitude-behaviour consistencies}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-34427}, year = {1984}, abstract = {To investigate the relationship between implicit psychological hypotheses and explicit empirical findings, summaries of twenty published studies on attitude-behaviour consistency were presented to a sample of forty-eight psychology undergraduates. Subjects were asked to estimate the percentage of agreement between attitudes and behaviour obtained by each study. Correlations between subjects' covariation judgements and empirically obtained attitude-behaviour consistencies were minimal and nonsignificant. Results are discussed in the light of more recent research on attitudebehaviour relationship.}, language = {en} } @misc{StieglitzFuchssHillmannetal.2007, author = {Stieglitz, Stefan and Fuchß, Christoph and Hillmann, Oliver and Lattemann, Christoph}, title = {Mobile learning by using ad hoc messaging network}, issn = {1867-5808}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19960}, year = {2007}, abstract = {The requirements of modern e-learning techniques change. Aspects such as community interaction, flexibility, pervasive learning and increasing mobility in communication habits become more important. To meet these challenges e-learning platforms must provide support on mobile learning. Most approaches try to adopt centralised and static e-learning mechanisms to mobile devices. However, often technically it is not possible for all kinds of devices to be connected to a central server. Therefore we introduce an application of a mobile e-learning network which operates totally decentralised with the help of an underlying ad hoc network architecture. Furthermore the concept of ad hoc messaging network (AMNET) is used as basis system architecture for our approach to implement a platform for pervasive mobile e-learning.}, language = {en} } @misc{StieglitzFuchssLattemann2007, author = {Stieglitz, Stefan and Fuchß, Christoph and Lattemann, Christoph}, title = {Mobile learning by using ad hoc messaging network}, issn = {1867-5808}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-19979}, year = {2007}, abstract = {The requirements of modern e-learning techniques change. Aspects such as community interaction, flexibility, pervasive learning and increasing mobility in communication habits become more important. To meet thesechallenges e-learning platforms must provide support on mobile learning. Most approaches try to adopt centralized and static elearning mechanisms to mobile devices. However, often technically it is not possible for all kinds of devices to be connected to a central server. Therefore we introduce an application of a mobile e-learning network which operates totally decentralized with the help of an underlying ad hoc network architecture. Furthermore the concept of ad hoc messaging network (AMNET) is used as basis system architecture for our approach to implement a platform for pervasive mobile elearning.}, language = {en} } @misc{Tavassoli2004, author = {Tavassoli, Gholam-Abbas}, title = {Islamic movements in Iran}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-9699}, year = {2004}, abstract = {The modernist Islamic Movement sought to reconcile modern values and Islamic faith and attempted to express these values through an Islamic discourse and to reform political, religious and educational institutions along modernist lines. However, such a movement in the Islamic Republic of Iran raised controversy among the traditional leadership and secular intellectual groups. The aim of this paper is to discuss how far modernist Islam could progress in an islamic republic with an old tradition.}, language = {en} } @misc{ThiekenBesselKienzleretal.2016, author = {Thieken, Annegret and Bessel, Tina and Kienzler, Sarah and Kreibich, Heidi and M{\"u}ller, Meike and Pisi, Sebastian and Schr{\"o}ter, Kai}, title = {The flood of June 2013 in Germany}, series = {National Hazards Earth System Science}, journal = {National Hazards Earth System Science}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-97207}, pages = {21}, year = {2016}, abstract = {In June 2013, widespread flooding and consequent damage and losses occurred in Central Europe, especially in Germany. This paper explores what data are available to investigate the adverse impacts of the event, what kind of information can be retrieved from these data and how well data and information fulfil requirements that were recently proposed for disaster reporting on the European and international levels. In accordance with the European Floods Directive (2007/60/EC), impacts on human health, economic activities (and assets), cultural heritage and the environment are described on the national and sub-national scale. Information from governmental reports is complemented by communications on traffic disruptions and surveys of flood-affected residents and companies. Overall, the impacts of the flood event in 2013 were manifold. The study reveals that flood-affected residents suffered from a large range of impacts, among which mental health and supply problems were perceived more seriously than financial losses. The most frequent damage type among affected companies was business interruption. This demonstrates that the current scientific focus on direct (financial) damage is insufficient to describe the overall impacts and severity of flood events. The case further demonstrates that procedures and standards for impact data collection in Germany are widely missing. Present impact data in Germany are fragmentary, heterogeneous, incomplete and difficult to access. In order to fulfil, for example, the monitoring and reporting requirements of the Sendai Framework for Disaster Risk Reduction 2015-2030 that was adopted in March 2015 in Sendai, Japan, more efforts on impact data collection are needed.}, language = {en} } @misc{ThielRomanoKurthsetal.2006, author = {Thiel, Marco and Romano, Maria Carmen and Kurths, J{\"u}rgen and Rolfs, Martin}, title = {Twin Surrogates to Test for Complex Synchronisation}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57231}, year = {2006}, abstract = {We present an approach to generate (multivariate) twin surrogates (TS) based on recurrence properties. This technique generates surrogates which correspond to an independent copy of the underlying system, i. e. they induce a trajectory of the underlying system starting at different initial conditions. We show that these surrogates are well suited to test for complex synchronisation and exemplify this for the paradigmatic system of R¨ossler oscillators. The proposed test enables to assess the statistical relevance of a synchronisation analysis from passive experiments which are typical in natural systems.}, language = {en} } @misc{ThielRomanoKurthsetal.2006, author = {Thiel, Marco and Romano, Maria Carmen and Kurths, J{\"u}rgen and Rolfs, Martin and Kliegl, Reinhold}, title = {Generating Surrogates from Recurrences}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-56906}, year = {2006}, abstract = {In this paper we present an approach to recover the dynamics from recurrences of a system and then generate (multivariate) twin surrogate (TS) trajectories. In contrast to other approaches, such as the linear-like surrogates, this technique produces surrogates which correspond to an independent copy of the underlying system, i. e. they induce a trajectory of the underlying system visiting the attractor in a different way. We show that these surrogates are well suited to test for complex synchronization, which makes it possible to systematically assess the reliability of synchronization analyses. We then apply the TS to study binocular fixational movements and find strong indications that the fixational movements of the left and right eye are phase synchronized. This result indicates that there might be one centre only in the brain that produces the fixational movements in both eyes or a close link between two centres.}, language = {en} } @misc{ThompsonKliegl1991, author = {Thompson, Laura A. and Kliegl, Reinhold}, title = {Adult age effects of plausibility on memory : the role of time constraints during encoding}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-40347}, year = {1991}, abstract = {We investigated the role of training-induced knowledge Schemas and encoding time on adult age differences in recall. High-plausible (schema coherent) words were recalled better than lowplausible (schema discrepant) words in both age groups. This difference was larger for old-adults than for young adults for presentation times ranging from 3 s to 11 s per word. After equating participants in overall recall (i.e., at 50\% correct) by dynamic adjustment of presentation time, old adults again showed a stronger plausibility effect than young adults when recall was above criterion. In a second experiment with self-paced encoding, old adults used more time than young adults only for low-plausible pairs, yet they still remembered fewer of them. In a third experiment, both age groups preferred to imagine high- rather than low-plausible words, but this effect was more pronounced in old adults. The results indicate that, compared with young adults, old adults find it particularly difficult to form elaborative mental images of schema-discrepant information under a wide variety of time constraints during encoding. Results are discussed in relation to explanations based on age-related mental slowing.}, language = {en} } @misc{TremblayBlancoRey2015, author = {Tremblay, Jean Christophe and Blanco-Rey, Maria}, title = {Manipulating interfacial hydrogens at palladium via STM}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-99511}, pages = {11}, year = {2015}, abstract = {In this contribution, we provide a detailed dynamical analysis of the interfacial hydrogen migration mediated by scanning tunneling microscopy (STM). Contributions from the STM-current and from the non-adiabatic couplings are taken into account using only first principle models. The slight asymmetry of the tunnelling rates with respect to the potential bias sign inferred from experimental observations is reproduced by weighting the contributions of the metal acceptor-donor states for the propagation of the impinging electrons. The quasi-thermal inelastic collision mechanism is treated perturbatively. The influence of hydrogen pre-coverage is also investigated using new potential energy surfaces obtained from periodic density functional theory calculations. Fully quantum dynamical simulations of the system evolution are performed by solving the Pauli master equation, providing insight into the reaction mechanism of STM manipulation of subsurface hydrogens. It is observed that the hydrogen impurity favors resurfacing over occupation of the bulk and subsurface sites whenever possible. The present simulations give strong indication that the experimentally observed protuberances after STM-excitation are due to hydrogen accumulating in the vicinity of the surface.}, language = {en} } @misc{TsukamotoHeabelValencaetal.2008, author = {Tsukamoto, Junko and Heabel, Sophie and Valenca, Gustavo P. and Peter, Martin and Franco, Telma}, title = {Enzymatic direct synthesis of acrylic acid esters of mono- and disaccharides}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-42652}, year = {2008}, abstract = {BACKGROUND: There is an increased need to replace materials derived from fossil sources by renewables. Sugar-cane derived carbohydrates are very abundant in Brazil and are the cheapest sugars available in the market, with more than 400 million tons of sugarcane processed in the year 2007. The objective of this work was to study the preparation of sugar acrylates from free sugars and free acrylic acid, thus avoiding the previous preparation of protected sugar derivatives, such as glycosides, or activated acrylates, such as vinyl acrylate. RESULTS: Lipase catalyzed esterification of three mono- and two disaccharides with acrylic acid, in the presence or absence of molecular sieves was investigated. The reactions were monitored by high-performance liquid chromatography (HPLC) and the products were analyzed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. The main products are mono- and diacrylates, while higher esters are formed as minor products. The highest conversion to sugar acrylates was observed for the D-glucose and D-fructose, followed by D-xylose and D-maltose. Molecular sieves had no pronounced effect on the conversion CONCLUSIONS: A feasible method is described to produce and to characterize sugar acrylates, including those containing more than two acrylate groups. The process for production of these higher esters could potentially be optimized further to produce molecules for cross-linking in acrylate polymerization and other applications. The direct enzymatic esterification of free carbohydrates with acrylic acid is unprecedented.}, language = {en} } @misc{TsukrukMischenkoKoeberleetal.1992, author = {Tsukruk, Vladimir and Mischenko, Nikolay and K{\"o}berle, Peter and Laschewsky, Andr{\´e}}, title = {The structural order of some novel ionic polymers; 2. : Models of molecular packing}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17256}, year = {1992}, abstract = {The molecular packing and spatial correlations of two isomeric zwitterionic polymethacrylates and one polyacrylate analog are studied by means of X-ray analysis and conformational calculations. The analysis of the correlation functions and density distribution profiles suggest a double-layered molecular packing which is discussed for the three polymers investigated, with respect to their different chemical structures. Whereas the zwitterionic polymethacrylates studied exhibit liquid-like short-range order, the polyacrylate analog exhibits an ordered double-layered superstructure.}, language = {en} } @misc{Ungelenk2012, author = {Ungelenk, Johannes}, title = {Narcissus and Echo}, number = {186}, issn = {1866-8380}, doi = {10.25932/publishup-59996}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-599966}, pages = {142}, year = {2012}, abstract = {George Eliot's late novel Daniel Deronda tackles big, fundamental political questions that radiate from the societal circumstances of the novel's production and reach deep into our present-day life. The novel critically analyses the capitalistic, morally flawed and standard-less English society and narrates the title hero's proto-Zionist mission to found a Jewish nation that re-establishes history, meaning and ethical values. This study attempts to trace the novel's two models of society and time by bringing them into resonance with the myth of Narcissus and Echo famously rendered by Ovid. The unloving, self-referential, visual Narcissus is read as the model for the capitalistic world of spectacle and speculation. Echo's loving, memory-bearing voice forms an important part in the construction of the sublating unity of the Jewish nation-to-come. Guided by this resonance between George Eliot's novel and Ovid's myth pieces of critical theory and philosophy are woven into the study's fabric. The resulting analysis dissects and deconstructs the novel's fascinating and highly complex patterns of conditions of possibility for the fabrication of the redeeming Jewish nation, the very same conditions that the novel presents as the conditions of possibility for narrating a meaningful story.}, language = {en} } @misc{ValsecchiDimigenKliegletal.2009, author = {Valsecchi, Matteo and Dimigen, Olaf and Kliegl, Reinhold and Sommer, Werner and Turatto, Massimo}, title = {Microsaccadic Inhibition and P300 Enhancement in a Visual Oddball Task}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57170}, year = {2009}, abstract = {It has recently been demonstrated that the presentation of a rare target in a visual oddball paradigm induces a prolonged inhibition of microsaccades. In the field of electrophysiology, the amplitude of the P300 component in event-related potentials (ERP) has been shown to be sensitive to the stimulus category (target vs. non target) of the eliciting stimulus, its overall probability, and the preceding stimulus sequence. In the present study we further specify the functional underpinnings of the prolonged microsaccadic inhibition in the visual oddball task, showing that the stimulus category, the frequency of a stimulus and the preceding stimulus sequence influence microsaccade rate. Furthermore, by co-recording ERPs and eye-movements, we were able to demonstrate that, despite being largely sensitive to the same experimental manipulation, the amplitude of P300 and the microsaccadic inhibition predict each other very weakly, and thus constitute two independent measures of the brain's response to rare targets in the visual oddball paradigm.}, language = {en} } @misc{WackervonElert2001, author = {Wacker, Alexander and von Elert, Eric}, title = {Polyunsaturated fatty acids : evidence for non-substitutable biochemical resources in Daphnia galeata}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17587}, year = {2001}, abstract = {The factors that determine the efficiency of energy transfer in aquatic food webs have been investigated for many decades. The plant-animal interface is the most variable and least predictable of all levels in the food web. In order to study determinants of food quality in a large lake and to test the recently proposed central importance of the long-chained eicosapentaenoic acid (EPA) at the pelagic producer-grazer interface, we tested the importance of polyunsaturated fatty acids (PUFAs) at the pelagic producerconsumer interface by correlating sestonic food parameters with somatic growth rates of a clone of Daphnia galeata. Daphnia growth rates were obtained from standardized laboratory experiments spanning one season with Daphnia feeding on natural seston from Lake Constance, a large pre-alpine lake. Somatic growth rates were fitted to sestonic parameters by using a saturation function. A moderate amount of variation was explained when the model included the elemental parameters carbon (r2 = 0.6) and nitrogen (r2 = 0.71). A tighter fit was obtained when sestonic phosphorus was incorporated (r2 = 0.86). The nonlinear regression with EPA was relatively weak (r2 = 0.77), whereas the highest degree of variance was explained by three C18-PUFAs. The best (r2 = 0.95), and only significant, correlation of Daphnia's growth was found with the C18-PUFA α-linolenic acid (α-LA; C18:3n-3). This correlation was weakest in late August when C:P values increased to 300, suggesting that mineral and PUFA-limitation of Daphnia's growth changed seasonally. Sestonic phosphorus and some PUFAs showed not only tight correlations with growth, but also with sestonic α-LA content. We computed Monte Carlo simulations to test whether the observed effects of α-LA on growth could be accounted for by EPA, phosphorus, or one of the two C18-PUFAs, stearidonic acid (C18:4n-3) and linoleic acid (C18:2n-6). With >99 \% probability, the correlation of growth with α-LA could not be explained by any of these parameters. In order to test for EPA limitation of Daphnia's growth, in parallel with experiments on pure seston, growth was determined on seston supplemented with chemostat-grown, P-limited Stephanodiscus hantzschii, which is rich in EPA. Although supplementation increased the EPA content 80-800x, no significant changes in the nonlinear regression of the growth rates with α-LA were found, indicating that growth of Daphnia on pure seston was not EPA limited. This indicates that the two fatty acids, EPA and α-LA, were not mutually substitutable biochemical resources and points to different physiological functions of these two PUFAs. These results support the PUFA-limitation hypothesis for sestonic C:P < 300 but are contrary to the hypothesis of a general importance of EPA, since no evidence for EPA limitation was found. It is suggested that the resource ratios of EPA and α-LA rather than the absolute concentrations determine which of the two resources is limiting growth.}, language = {en} } @misc{WackervonElert2002, author = {Wacker, Alexander and von Elert, Eric}, title = {Strong influences of larval diet history on subsequent post-settlement growth in the freshwater mollusc Dreissena polymorpha}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17627}, year = {2002}, abstract = {Significant seasonal variation in size at settlement has been observed in newly settled larvae of Dreissena polymorpha in Lake Constance. Diet quality, which varies temporally and spatially in freshwater habitats, has been suggested as a significant factor influencing life history and development of freshwater invertebrates. Accordingly, experiments were conducted with field-collected larvae to test the hypothesis that diet quality can determine planktonic larval growth rates, size at settlement and subsequent post-metamorphic growth rates. Larvae were fed one of two diets or starved. One diet was composed of cyanobacterial cells which are deficient in polyunsaturated fatty acids (PUFAs), and the other was a mixed diet rich in PUFAs. Freshly metamorphosed animals from the starvation treatment had a carbon content per individual 70\% lower than that of larvae fed the mixed diet. This apparent exhaustion of larval internal reserves resulted in a 50\% reduction of the postmetamorphic growth rates. Growth was also reduced in animals previously fed the cyanobacterial diet. Hence, low food quantity or low food quality during the larval stage of D. polymorpha lead to irreversible effects for postmetamorphic animals, and is related to inferior competitive abilities.}, language = {en} }