TY - JOUR A1 - Emmerling, Franziska A1 - Orgzall, Ingo A1 - Reck, Günter A1 - Schulz, Burkhard W. A1 - Stockhause, Sabine A1 - Schulz, Burkhard T1 - Structures of substituted di-aryl-1, 3,4-oxadiazole derivatives: 2,5-bis(pyridyl)- and 2,5-bis(aminophenyl)-substitution JF - Journal of molecular structure N2 - Crystal structures of four different di-aryl-1,3,4-oxadiazole compounds (aryl = 2-pyridyl-, 3-pyridyl-, 2-aminophenyl-, 3-aminophenyl-) are determined. Crystallization of di(2-pyridyl)-1,3,4-oxadiazole yielded monoclinic and triclinic polymorphs. The structures are characterized by the occurrence of pi-pi interactions. Additionally, in case of the aminophenyl compounds intra- as well as intermolecular hydrogen bonds are found that influence the packing motif as well. Since these molecules are often used as ligands in metal-organic complexes similarities and differences of the molecular conformation between the molecules in the pure crystals and that of the ligands in the complexes are discussed. (c) 2006 Elsevier B.V. All rights reserved. KW - crystal structure KW - 1,3,4-oxadiazole KW - molecular conformation KW - hydrogen bonds Y1 - 2006 U6 - https://doi.org/10.1016/j.molstruc.2006.03.076 SN - 0022-2860 VL - 800 IS - 1-3 SP - 74 EP - 84 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Frübing, Peter A1 - Kremmer, Alexander A1 - Gerhard, Reimund A1 - Spanoudaki, Anna A1 - Pissis, Polycarpos T1 - Relaxation processes at the glass transition in polyamide 11: From rigidity to viscoelasticity JF - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr N2 - Relaxation processes associated with the glass transition in nonferroelectric and ferroelectric polyamide (PA) 11 are investigated by means of differential scanning calorimetry, dynamic mechanical analysis, and dielectric relaxation spectroscopy (DRS) in order to obtain information about the molecular mobility within the amorphous phase. In particular, the effects of melt quenching, cold drawing, and annealing just below the melting region are studied with respect to potential possibilities and limitations for improving the piezoelectric and pyroelectric properties of PA 11. A relaxation map is obtained from DRS that shows especially the crossover region where the cooperative alpha relaxation and the local beta relaxation merge into a single high-temperature process. No fundamental difference between quenched, cold-drawn, and annealed films is found, though in the cold-drawn (ferroelectric) film the alpha relaxation is suppressed and slowed down, but it is at least partly recovered by subsequent annealing. It is concluded that there exists an amorphous phase in all structures, even in the cold-drawn film. The amorphous phase can be more rigid or more viscoelastic depending on preparation. Cold drawing not only leads to crystallization in a ferroelectric form but also to higher rigidity of the remaining amorphous phase. Annealing just below the melting region after cold drawing causes a stronger phase separation between the crystalline phase and a more viscoelastic amorphous phase. Y1 - 2006 U6 - https://doi.org/10.1063/1.2360266 SN - 0021-9606 VL - 125 IS - 12 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Zhou, Changsong A1 - Zemanova, Lucia A1 - Zamora, Gorka A1 - Hilgetag, Claus C. A1 - Kurths, Jürgen T1 - Hierarchical organization unveiled by functional connectivity in complex brain networks JF - Physical review letters N2 - How do diverse dynamical patterns arise from the topology of complex networks? We study synchronization dynamics in the cortical brain network of the cat, which displays a hierarchically clustered organization, by modeling each node (cortical area) with a subnetwork of interacting excitable neurons. We find that in the biologically plausible regime the dynamics exhibits a hierarchical modular organization, in particular, revealing functional clusters coinciding with the anatomical communities at different scales. Our results provide insights into the relationship between network topology and functional organization of complex brain networks. Y1 - 2006 U6 - https://doi.org/10.1103/PhysRevLett.97.238103 SN - 0031-9007 SN - 1079-7114 VL - 97 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Fudickar, Werner A1 - Linker, Torsten T1 - Imaging by sensitized oxygenations of photochromic anthracene films BT - Examination of effects that improve performance and reversibility JF - Chemistry - a European journal N2 - The aliphatic anthracene compound 1 and the oligomeric anthracene 2 were synthesized. Thin films of 1 and 2 mixed with the sensitizers tetraphenylporphyrin (TPP) and methylene blue (MB) were irradiated with visible light in air. Upon formation of singlet oxygen, the anthracene units were converted quantitatively to the corresponding endoperoxides. Heating of the irradiated samples afforded the parent anthracenes with high yields. Here, we demonstrate that the kinetics and reversibility of this reaction strongly depend on the microenvironment of the anthracene groups in the two compounds. The photooxidation of thin films of I is accompanied by interesting changes in the morphology of the film and allows the first application of 1 as a nondestructive negative-tone photo-resist for lithography and as an oxidizing ink. The morphology of 2 remained unchanged after photooxidation as a result of the stabilizing oligomer backbone. This stabilizing effect significantly improves the photochromic performance of 2. The reversibility of the photooxidation is very high (> 90%) for oligomeric films of 2 after several cycles of irradiation and beating. Decomposition of the anthracene and a loss of the activity of the sensitizer diminish slightly the performance of the monomeric species. KW - anthracenes KW - lithography KW - photochromism KW - singlet oxygen KW - thin films Y1 - 2006 U6 - https://doi.org/10.1002/chem.200600387 SN - 0947-6539 VL - 12 SP - 9276 EP - 9283 PB - WILEY‐VCH CY - Weinheim ER - TY - JOUR A1 - Bordihn, Henning A1 - Fernau, Henning A1 - Holzer, Markus A1 - Manca, Vincenzo A1 - Martin-Vide, Carlos T1 - Iterated sequential transducers as language generating devices JF - Theoretical computer science N2 - Iterated finite state sequential transducers are considered as language generating devices. The hierarchy induced by the size of the state alphabet is proved to collapse to the fourth level. The corresponding language families are related to the families of languages generated by Lindenmayer systems and Chomsky grammars. Finally, some results on deterministic and extended iterated finite state transducers are established. KW - finite state sequential transducers KW - state complexity KW - Lindenmayer systems Y1 - 2006 U6 - https://doi.org/10.1016/j.tcs.2006.07.059 SN - 0304-3975 VL - 369 IS - 1 SP - 67 EP - 81 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schröder, Boris A1 - Seppelt, Ralf T1 - Analysis of pattern-process interactions based on landscape models - Overview, general concepts, and methodological issues JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - Pattern-process analysis is one of the main threads in landscape ecological research. It aims at understanding the complex relationships between ecological processes and landscape patterns, identifying the underlying mechanisms and deriving valid predictions for scenarios of landscape change and its consequences. Today, various studies cope with these tasks through so called "landscape modelling" approaches. They integrate different aspects of heterogeneous and dynamic landscapes and model different driving forces, often using both statistical and process-oriented techniques. We identify two main approaches to deal with the analysis of pattern-process interactions: the first starts with pattern detection, pattern description and pattern analysis, the second with process description, simulation and pattern generation. Focussing on the interplay between these two approaches, landscape analysis and landscape modelling will improve our understanding of pattern-process interactions. The comparison of simulated and observed pattern is a prerequisite for both approaches. Therefore, we identify a set of quantitative, robust, and reproducible methods for the analysis of spatiotemporal patterns that is a starting point for a standard toolbox for ecologists as major future challenge and suggest necessary further methodological developments. (c) 2006 Elsevier B.V. All rights reserved. KW - pattern-process interrelationship KW - landscape analysis KW - landscape modelling KW - simulation KW - inverse modelling KW - pattern description KW - wavelet analysis Y1 - 2006 U6 - https://doi.org/10.1016/j.ecolmodel.2006.05.036 SN - 0304-3800 VL - 199 IS - 4 SP - 505 EP - 516 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Tietjen, Britta A1 - Huth, Andreas T1 - Modelling dynamics of managed tropical rainforests - An aggregated approach JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - The overuse of rainforests in the last century and its consequences necessitate a rethinking of logging policies. To this end models have been developed to simulate rainforest dynamics and to allow optional management strategies to be evaluated. Parameterisation of presently existing models for a certain site needs a lot of work, thus the parameterisation effort is too high to apply the models to a wide range of rainforests. Hence, in this paper we introduce the simplified model FORREG using the knowledge we have gained from a more complex model, FORMIX3-Q. The FORREG model uses differential equations to determine the volume growth of three successional species groups. Parameterisation is simplified by a genetic algorithm, which determines the required internal model parameters from characteristics of the forest dynamics. The new model is employed to assess the sustainability of various logging policies in terms of yield and damage. Results for three forests are discussed: (1) the tropical lowland rain forest in the Deramakot Forest Reserve, (2) the Lambir National Park in Malaysia and (3) a subtropical forest in Paraguay. Our model reproduces both undisturbed forest dynamics and dynamics of logged forests simulated with FORMIX3-Q very well. However, the resultant volumes of yield and damage differ slightly from those gained by FORMIX3-Q if short logging cycles are simulated. Choosing longer logging cycles leads to a good correspondence of both models. For the Deramakot Forest Reserve different logging cycles are compared and discussed. (c) 2006 Elsevier B.V. All rights reserved. KW - aggregation KW - differential equation KW - forest model KW - genetic algorithm KW - logging KW - tropical rainforest Y1 - 2006 U6 - https://doi.org/10.1016/j.ecolmodel.2005.11.045 SN - 0304-3800 VL - 199 IS - 4 SP - 421 EP - 432 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hattermann, Fred A1 - Krysanova, Valentina A1 - Habeck, Anja A1 - Bronstert, Axel T1 - Integrating wetlands and riparian zones in river basin modelling JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog N2 - Wetlands, and in particular riparian wetlands, represent an interface between the catchment area and the aquatic environment. They control the exchange of water and related chemical fluxes from the upper catchment area to surface waters like streams and lakes. Their influence on water and nutrient balances has been investigated mainly at the patch scale. In this study an attempt was made (a) to integrate riparian zones and wetlands into eco-hydrological river basin modelling, and (b) to quantify the impacts of riparian wetland processes on water and nutrient fluxes in a meso-scale catchment located in the northeastern German lowland. The investigation was performed by analysing hydro-chemical field data and applying the eco-hydrological model SWIM (Soil and Water Integrated Model), which was extended to reproduce the relevant water and nutrient flows and retention processes at the catchment scale in general, and in riparian zones and wetlands in particular. The main extensions introduced in the model were: (1) implementation of daily groundwater table dynamics at the hydrotope level, (2) implementation of water and nutrient uptake by plants from groundwater in riparian zones and wetlands, and (3) assessment of nutrient retention in groundwater and interflow. The simulation results indicate that wetlands, though they represent relatively small parts of the total catchment area, may have a significant impact on the overall water and nutrient balances of the catchment. The uncertainty of the simulation results is considerably high, with the main sources of uncertainty being the model parameters representing the geo-hydrology and the input data for land use management. (c) 2006 Elsevier B.V. All rights reserved. KW - riparian zones KW - wetlands KW - water quality KW - groundwater dynamics KW - nutrient retention KW - integrated river basin modelling Y1 - 2006 U6 - https://doi.org/10.1016/j.ecolmodel.2005.06.012 SN - 0304-3800 VL - 199 IS - 4 SP - 379 EP - 392 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Seppelt, Ralf A1 - Schröder, Boris T1 - Pattern and processes of dynamic mosaic landscapes JF - Ecological modelling : international journal on ecological modelling and engineering and systems ecolog Y1 - 2006 U6 - https://doi.org/10.1016/j.ecolmodel.2006.06.011 SN - 0304-3800 VL - 199 IS - 4 SP - 377 EP - 378 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Mechau, Norman A1 - Saphiannikova, Marina A1 - Neher, Dieter T1 - Molecular tracer diffusion in thin azobenzene polymer layers JF - Applied physics letters N2 - Translational diffusion of fluorescent tracer molecules in azobenzene polymer layers is studied at different temperatures and under illumination using the method of fluorescence recovery after photobleaching. Diffusion is clearly observed in the dark above the glass transition temperature, while homogeneous illumination at 488 nm and 100 mW/cm(2) does not cause any detectable diffusion of the dye molecules within azobenzene layers. This implies that the viscosity of azobenzene layers remains nearly unchanged under illumination with visible light in the absence of internal or external forces. (c) 2006 American Institute of Physics. Y1 - 2006 U6 - https://doi.org/10.1063/1.2405853 SN - 0003-6951 VL - 89 IS - 25 PB - Elsevier CY - Melville ER - TY - JOUR A1 - Gandhimathi, V. M. A1 - Rajasekar, S. A1 - Kurths, Jürgen T1 - Vibrational and stochastic resonances in two coupled overdamped anharmonic oscillators JF - Modern physics letters : A, Particles and fields, gravitation, cosmology, nuclear physics N2 - We study the overdamped version of two coupled anharmonic oscillators under the influence of both low- and high-frequency forces respectively and a Gaussian noise term added to one of the two state variables of the system. The dynamics of the system is first studied in the presence of both forces separately without noise. In the presence of only one of the forces, no resonance behaviour is observed, however, hysteresis happens there. Then the influence of the high-frequency force in the presence of a low-frequency, i.e. biharmonic forcing, is studied. Vibrational resonance is found to occur when the amplitude of the high-frequency force is varied. The resonance curve resembles a stochastic resonance-like curve. It is maximum at the value of g at which the orbit lies in one well during one half of the drive cycle of the low-frequency force and in the other for the remaining half cycle. Vibrational resonance is characterized using the response amplitude and mean residence time. We show the occurrence of stochastic resonance behaviour in the overdamped system by replacing the high-frequency force by Gaussian noise. Similarities and differences between both types of resonance are presented. (c) 2006 Elsevier B.V. All rights reserved. KW - vibrational resonance KW - low-frequency force KW - high-frequency force KW - stochastic resonance KW - noise KW - mean residence time Y1 - 2006 U6 - https://doi.org/10.1016/j.physleta.2006.08.051 SN - 0375-9601 VL - 360 IS - 2 SP - 279 EP - 286 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Andrianov, Ivan A1 - Saalfrank, Peter T1 - Free vibrational relaxation of H adsorbed on a Si(100) surface investigated with the multi-configurational time-dependent Hartree method JF - Chemical physics letters N2 - The results of a quantum-mechanical study of vibrational relaxation of hydrogen adsorbed on a Si(100) surface with the multi-configurational time-dependent Hartree (MCTDH) method are presented. A two-dimensional subsystem is coupled non-linearly to a bath of harmonic oscillators (phonons of the Si bulk), and the relaxation of subsystem vibrations proceeds primarily via a two-phonon process. Characteristic times of the system evolution agree well with our previous perturbation theory study. The vibrational population decay is non-exponential, exhibiting pronounced recurrences due to finite bath size. The dependence of the lifetimes of the vibrational levels on the bath size and on the coupling details is investigated. Y1 - 2006 U6 - https://doi.org/10.1016/j.cplett.2006.11.067 SN - 0009-2614 VL - 433 SP - 91 EP - 96 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Selting, Margret T1 - Prosody as an activity-type distinctive signalling cue in conversation : the case of so-called 'astonished questions' in repair-initiation Y1 - 2006 ER - TY - JOUR A1 - Couper-Kuhlen, Elizabeth A1 - Selting, Margret T1 - Towards an interactional perspective on prosody and a prosodic perspective on interaction Y1 - 2006 ER - TY - BOOK ED - Couper-Kuhlen, Elizabeth ED - Selting, Margret T1 - Prosody in Conversation : Interactional Studies T3 - Studies in international sociolinguistics Y1 - 2006 SN - 978-0-521-02410-5 VL - 12 PB - Cambridge Univ. Press CY - Cambridge ET - 1. publ., digitally printed 1. paperback version ER - TY - JOUR A1 - Romano, Maria Carmen A1 - Thiel, Marco A1 - Kurths, Jürgen A1 - Rolfs, Martin A1 - Engbert, Ralf A1 - Kliegl, Reinhold T1 - Synchronization Analysis and Recurrence in Complex Systems Y1 - 2006 SN - 978-3-527-40623-4 ER - TY - JOUR A1 - Kunow, Rüdiger T1 - Architect of the Cosmopolitan Dream : Salman Rushdie Y1 - 2006 ER - TY - JOUR A1 - Kunow, Rüdiger T1 - The Enigma of Arrival Y1 - 2006 SN - 978-3-32311-955-5 ER - TY - JOUR A1 - Eckstein, Lars T1 - Alder, E., Hauck, D., Music and Literature: Music in the Works of Anthony Burgess and E.M. Forster - An Interdisciplinary Study; Tübingen, Francke, 2005 BT - Music and Literature: Music in the Works of Anthony Burgess and E.M. Forster - An Interdisciplinary Study Y1 - 2006 ER - TY - JOUR A1 - Eckstein, Lars A1 - Reinfandt, Christoph T1 - On dancing about architecture : words and music between cultural practise and transcendence Y1 - 2006 ER - TY - GEN A1 - Eckstein, Lars A1 - Reinfandt, Christoph T1 - The cultural validity of music in contemporary fiction T2 - Special Issues of Zeitschrift für Anglistik und Amerikanistik (ZAA) Y1 - 2006 SN - 3-8260-3365-5 VL - 54.2006,1 PB - Königshausen u. Neumann CY - Würzburg ER - TY - BOOK A1 - Eckstein, Lars T1 - Re-Membering the Black Atlantic : on the poetics and politics of literary memory T3 - Cross cultures Y1 - 2006 SN - 94-420-1958-1 VL - 84 PB - Rodopi CY - Amsterdam ER - TY - JOUR A1 - Zhou, Changsong A1 - Kurths, Jürgen T1 - Hierarchical synchronization in complex networks with heterogeneous degrees N2 - We study synchronization behavior in networks of coupled chaotic oscillators with heterogeneous connection degrees. Our focus is on regimes away from the complete synchronization state, when the coupling is not strong enough, when the oscillators are under the influence of noise or when the oscillators are nonidentical. We have found a hierarchical organization of the synchronization behavior with respect to the collective dynamics of the network. Oscillators with more connections (hubs) are synchronized more closely by the collective dynamics and constitute the dynamical core of the network. The numerical observation of this hierarchical synchronization is supported with an analysis based on a mean field approximation and the master stability function. (C) 2006 American Institute of Physics Y1 - 2006 UR - http://scitation.aip.org/getpdf/servlet/ GetPDFServlet?filetype=pdf&id=CHAOEH000016000001015104000001&idtype=cvips&doi=10.1063/1.2150381&prog=normal U6 - https://doi.org/10.1063/1.2150381 SN - 1054-1500 ER - TY - JOUR A1 - Zhou, Changsong A1 - Motter, Adilson E. A1 - Kurths, Jürgen T1 - Universality in the synchronization of weighted random networks N2 - Realistic networks display not only a complex topological structure, but also a heterogeneous distribution of weights in the connection strengths. Here we study synchronization in weighted complex networks and show that the synchronizability of random networks with a large minimum degree is determined by two leading parameters: the mean degree and the heterogeneity of the distribution of node's intensity, where the intensity of a node, defined as the total strength of input connections, is a natural combination of topology and weights. Our results provide a possibility for the control of synchronization in complex networks by the manipulation of a few parameters Y1 - 2006 UR - http://prl.aps.org/pdf/PRL/v96/i3/e034101 U6 - https://doi.org/10.1103/Physrevlett.96.034101 ER - TY - JOUR A1 - Zhou, Changsong A1 - Kurths, Jürgen T1 - Dynamical weights and enhanced synchronization in adaptive complex networks N2 - Dynamical organization of connection weights is studied in scale-free networks of chaotic oscillators, where the coupling strength of a node from its neighbors develops adaptively according to the local synchronization property between the node and its neighbors. We find that when complete synchronization is achieved, the coupling strength becomes weighted and correlated with the topology due to a hierarchical transition to synchronization in heterogeneous networks. Importantly, such an adaptive process enhances significantly the synchronizability of the networks, which could have meaningful implications in the manipulation of dynamical networks Y1 - 2006 UR - http://link.aps.org/doi/10.1103/PhysRevLett.96.164102 U6 - https://doi.org/10.1103/Physrevlett.96.164102 ER - TY - JOUR A1 - Zen, Achmad A1 - Saphiannikova, Marina A1 - Neher, Dieter A1 - Grenzer, Jörg A1 - Grigorian, Souren A. A1 - Pietsch, Ullrich A1 - Asawapirom, Udom A1 - Janietz, Silvia A1 - Scherf, Ullrich A1 - Lieberwirth, Ingo A1 - Wegner, Gerhard T1 - Effect of molecular weight on the structure and crystallinity of poly(3-hexylthiophene) N2 - Recently, two different groups have reported independently that the mobility of field-effect transistors made from regioregular poly(3-hexylthiophene) (P3HT) increases strongly with molecular weight. Two different models were presented: one proposing carrier trapping at grain boundaries and the second putting emphasis on the conformation and packing of the polymer chains in the thin layers for different molecular weights. Here, we present the results of detailed investigations of powders and thin films of deuterated P3HT fractions with different molecular weight. For powder samples, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) were used to investigate the structure and crystallization behavior of the polymers. The GPC investigations show that all weight fractions possess a rather broad molecular weight distribution. DSC measurements reveal a strong decrease of the crystallization temperature and, most important, a significant decrease of the degree of crystallinity with decreasing molecular weight. To study the structure of thin layers in lateral and vertical directions, both transmission electron microscopy (TEM) and X-ray grazing incidence diffraction (GID) were utilized. These methods show that thin layers of the low molecular weight fraction consist of well-defined crystalline domains embedded in a disordered matrix. We propose that the transport properties of layers prepared from fractions of poly(3-hexylthiophene) with different molecular weight are largely determined by the crystallinity of the samples and not by the perfection of the packing of the chains in the individual crystallites Y1 - 2006 UR - http://pubs.acs.org/doi/full/10.1021/ma0521349 U6 - https://doi.org/10.1021/Ma0521349 ER - TY - JOUR A1 - Thiel, Marco A1 - Romano, Maria Carmen A1 - Kurths, Jürgen A1 - Rolfs, Martin A1 - Kliegl, Reinhold T1 - Twin surrogates to test for complex synchronisation N2 - 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 Rossler oscillators. The proposed test enables to assess the statistical relevance of a synchronisation analysis from passive experiments which are typical in natural systems Y1 - 2006 UR - http://www.mendeley.com/research/twin-surrogates-to-test-for-complex-synchronisation/#page-1 U6 - https://doi.org/10.1209/epl/i2006-10147-0 ER - TY - JOUR A1 - Strehmel, Veronika A1 - Laschewsky, André A1 - Stoesser, Reinhard A1 - Zehl, Andrea A1 - Herrmann, Werner T1 - Mobility of spin probes in ionic liquids N2 - The spin probes TEMPO, TEMPOL, and CAT-1 were used to investigate microviscosity and micropolarity of imidazolium based ionic liquids bearing either tetrafluoroborate or hexafluorophosphate as anions and a variation of the substitution at the imidazolium ion. The average rotational correlation times (r) obtained by complete simulation of the X-band ESR spectra of TEMPO, TEMPOL, and CAT-1 increase with increasing viscosity of the ionic liquid although no Stokes Einstein behavior is observed. This is caused by microviscosity effects of the ionic liquids shown by application of the Gierer-Wirtz theory. Interestingly, the jump of the probe molecule into the free volume of the ionic liquids is a nonactivated process. The hyperfine coupling constants (A(iso) (N-14)) of TEMPO and TEMPOL dissolved in the ionic liquids do not depend on the structure of the ionic liquids. The A(iso) (N-14) values show a micropolarity of the ionic liquids that is comparable with methylenchloride in case of TEMPO and with dimethylsulfoxide in case of TEMPOL. Micropolarity monitored by CAT-1 strongly depends on structural variation of the ionic liquid. CAT-1 dissolved in imidazolium salts substituted with shorter alkyl chains at the nitrogen atom exhibits a micropolarity comparable with dimethylsulfoxide. A significant lower micropolarity is found for imidazolium. salts bearing a longer alkyl substituent at the nitrogen atom or a methyl substituent at C-2. Copyright (c) 2006 John Wiley & Sons, Ltd Y1 - 2006 UR - http://onlinelibrary.wiley.com/doi/10.1002/poc.1072/pdf U6 - https://doi.org/10.1002/poc.1072 ER - TY - JOUR A1 - Stepan, H A1 - Faber, R A1 - Wessel, Niels A1 - Wallukat, Gerd A1 - Schultheiss, H. P. A1 - Walther, T T1 - Relation between circulating angiotensin II type 1 receptor agonistic autoantibodies and soluble fms-like tyrosine kinase 1 in the pathogenesis of preeclampsia N2 - Context: Placental and circulatory soluble fms-like tyrosine kinase 1 (sFlt1) has proven to be elevated in pregnant women with preeclampsia, a disease characterized by hypertension, proteinuria, and endothelial dysfunction. Recent studies also demonstrated an autoantibody against the angiotensin II type 1 (AT1) receptor (AT1-AA) in that disease. Objective: Both factors are discussed as key players in the etiology of preeclampsia. However, it has not yet been clarified whether these two circulating factors correlate and whether synergy determines the severity of pathology. Design: AT1-AA was retrospectively determined by a bioassay and sFlt1 by an ELISA. Patients: Serum from second-trimester pregnancies with normal or abnormal uterine perfusion and in women at term with or without pregnancy pathology was analyzed. Results: Most of the preeclamptic patients were characterized by high sFlt1 levels and the presence of AT1-AA, although the agonistic effects of the antibody did not correlate with the sFlt1 concentrations (P = 0.85). Although AT1- AA was also detected in second-trimester pregnancies evidencing abnormal uterine perfusion without later pathology, sFlt1 was not significantly elevated in these pregnancies, compared with those with normal uterine perfusion. However, whereas women with abnormal perfusion and later pregnancy pathology did not differ in AT1-AA, compared with those with normal outcome, sFlt1 was significantly increased. Again, the two factors did not correlate (P = 0.15). Conclusions: We conclude that AT1-AA bioactivity and sFlt1 concentrations do not correlate, are not mutually dependent, and are thus probably involved in distinct pathogenetic mechanisms. Both factors in combination may not be causative for the early impaired trophoblast invasion and pathological uterine perfusion Y1 - 2006 UR - http://jcem.endojournals.org/content/91/6/2424.full U6 - https://doi.org/10.1210/Jc.2005-2698 ER - TY - JOUR A1 - Sommer, Michael A1 - Kaczorek, Danuta A1 - Kuzyakov, Yakov A1 - Breuer, Jörn T1 - Silicon pools and fluxes in soils and landscapes : a review N2 - Silicon (Si) is the second-most abundant element in the earth's crust. In the pedosphere, however, huge spans of Si contents occur mainly caused by Si redistribution in soil profiles and landscapes. Here, we summarize the current knowledge on the different pools and fluxes of Si in soils and terrestrial biogeosystems. Weathering and subsequent release of soluble Si may lead to (1) secondarily bound Si in newly formed Al silicates, (2) amorphous silica precipitation on surfaces of other minerals, (3) plant uptake, formation of phytogenic Si, and subsequent retranslocation to soils, (4) translocation within soil profiles and formation of new horizons, or (5) translocation out of soils (desilication). The research carried out hitherto focused on the participation of Si in weathering processes, especially in clay neoformation, buffering mechanisms for acids in soils or chemical denudation of landscapes. There are, however, only few investigations on the characteristics and controls of the low-crystalline, almost pure silica compounds formed during pedogenesis. Further, there is strong demand to improve the knowledge of (micro)biological and rhizosphere processes contributing to Si mobilization, plant uptake, and formation of phytogenic Si in plants, and release due to microbial decomposition. The contribution of the biogenic Si sources to Si redistribution within soil profiles and desilication remains unknown concerning the pools, rates, processes, and driving forces. Comprehensive studies considering soil hydrological, chemical, and biological processes as well as their interactions at the scale of pedons and landscapes are necessary to make up and model the Si balance and to couple terrestrial processes with Si cycle of limnic, fluvial, or marine biogeosystems Y1 - 2006 ER - TY - JOUR A1 - Sobel, Edward A1 - Chen, Jie A1 - Heermance, Richard V. T1 - Late Oligocene-Early Miocene initiation of shortening in the Southwestern Chinese Tian Shan : implications for Neogene shortening rate variations N2 - The Cenozoic Tian Shan is one of the preeminent examples of an intracontinental orogen. However, there remains a significant controversy over when deformation related to the India-Asia collision commenced and therefore how shortening within the mountains has been partitioned over time. One approach has been to look at the modem shortening rate as measured by geodetic studies, combined with estimates of the total shortening across the range and extrapolate backwards. This approach suggests that the onset of range construction was ca. 10 Ma [K.Y. Abdrakhmatov, S.A. Aldazhanov, B.H. Hager, M.W Hamburger, T.A. Herring, K.B. Kalabaev, K.B. Kalabayev, V.I. Makarov, P. Molnar, S.V Panasyuk, M.T. Prilepin, R.E. Reilinger, I.S. Sadybakasov, B.J. Souter, Y.A. Trapeznikov, V.Y. Tsurkov, A.V. Zubovich, Relatively recent construction of the Tien Shan inferred from GPS measurements of present-day crustal deformation rates, Nature 384 (6608) (1996) 450-453]. An alternate method is to determine the age of the onset of exhumation using thermochronology. We present 19 new apatite fission-track (AFT) results from the southwestern Chinese portion of the belt; this region represents the first area exhumed during the late Tertiary along a transect at ca. 76 degrees E. Exhumation commenced at the Oligocene-Miocene boundary (similar to 24 Ma) along the Maidan and Muziduke thrusts, which bound the southern side of the Kokshaal range. Subsequently, deformation propagated ca. 20 km south to the Kashi basin- bounding thrust (KBT), which was exhumed by no earlier than 18.9 +/- 3.3 Ma. Three detrital AFT samples from Plio- Pleistocene strata deposited ca. 20 km farther south contain fission track grain age peaks that young monotonically upwards from 20.9 + 7.0/- 5.3 Ma to 15.9 + 5.4/- 4.0 Ma with a fairly constant lag time of 16 to 18 Ma. These ages, combined with structural data, suggest that both the hanging wall and the footwall of the KBT experienced a renewed episode of exhumation during the latest Cenozoic. The discrepancy between the Late Oligocene-Miocene initiation of significant exhumation shown herein and the 10 Ma initiation estimate from geodesy suggests that the Tian Shan has undergone a complex Late Cenozoic shortening history. Assuming that the present shortening rate could account for the total amount of Cenozoic shortening in 10 Ma and realizing that shortening initiated at least 15 Myr earlier, we conclude that the shortening rate must have varied over time, possibly in pulsed-southward migrating events, and that the present rate may not reflect the average rate since initiation of range uplift. (c) 2006 Elsevier B.V. All rights reserved Y1 - 2006 UR - http://www.sciencedirect.com/science/article/pii/S0012821X06002834 U6 - https://doi.org/10.1016/j.epsl.2006.03.048 ER - TY - JOUR A1 - Skirycz, Aleksandra A1 - Reichelt, Michael A1 - Burow, Meike A1 - Birkemeyer, Claudia Sabine A1 - Rolcik, Jacub A1 - Kopka, Joachim A1 - Zanor, Maria Ines A1 - Gershenzon, Jonathan A1 - Strnad, Miroslav A1 - Szopa, Jan A1 - Müller-Röber, Bernd A1 - Witt, Isabell T1 - DOF transcription factor AtDof1.1 (OBP2) is part of a regulatory network controlling glucosinolate biosynthesis in Arabidopsis N2 - Glucosinolates are a group of secondary metabolites that function as defense substances against herbivores and micro-organisms in the plant order Capparales. Indole glucosinolates (IGS), derivatives of tryptophan, may also influence plant growth and development. In Arabidopsis thaliana, indole-3-acetaldoxime (IAOx) produced from tryptophan by the activity of two cytochrome P450 enzymes, CYP79B2 and CYP79B3, serves as a precursor for IGS biosynthesis but is also an intermediate in the biosynthetic pathway of indole-3-acetic acid (IAA). Another cytochrome P450 enzyme, CYP83B1, funnels IAOx into IGS. Although there is increasing information about the genes involved in this biochemical pathway, their regulation is not fully understood. OBP2 has recently been identified as a member of the DNA-binding-with-one- finger (DOF) transcription factors, but its function has not been studied in detail so far. Here we report that OBP2 is expressed in the vasculature of all Arabidopsis organs, including leaves, roots, flower stalks and petals. OBP2 expression is induced in response to a generalist herbivore, Spodoptera littoralis, and by treatment with the plant signalling molecule methyl jasmonate, both of which also trigger IGS accumulation. Constitutive and inducible over- expression of OBP2 activates expression of CYP83B1. In addition, auxin concentration is increased in leaves and seedlings of OBP2 over-expression lines relative to wild-type, and plant size is diminished due to a reduction in cell size. RNA interference-mediated OBP2 blockade leads to reduced expression of CYP83B1. Collectively, these data provide evidence that OBP2 is part of a regulatory network that regulates glucosinolate biosynthesis in Arabidopsis Y1 - 2006 UR - http://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2006.02767.x/full ER - TY - JOUR A1 - Schmidt, Bernd A1 - Nave, Stefan T1 - Control of ring size selectivity by substrate directable RCM N2 - Hydroxy groups may exert strong catalyst-directing effects in olefin metathesis reactions, which are exploited for a ring size-selective RCM reaction Y1 - 2006 UR - http://pubs.rsc.org/en/content/articlehtml/2006/cc/b604359c U6 - https://doi.org/10.1039/B604359c ER - TY - JOUR A1 - Schmidt, Bernd T1 - Olefin metathesis and isomerization : from undesired side reactions to useful synthetic methodology N2 - Conversion of ruthenium carbene complexes to ruthenium hydride complexes by organometallic transformations in situ opens up interesting synthetic perspectives. In this account the use of Grubbs' catalyst to synthesize pent-4- enals selectively from diallyl- and allyl homoallyl ethers and scope and limitations of a Tandem RCM-isomerization sequence for the synthesis of cyclic enol ethers are discussed. (c) 2006 Elsevier B.V. All rights reserved Y1 - 2006 UR - http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TGM-4JT9C6D- 2&_user=1584062&_coverDate=07%2F19%2F2006&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_sea rchStr U6 - https://doi.org/10.1016/j.molcata.2006.03.026 ER - TY - JOUR A1 - Schmid, Karl J. A1 - Torjek, Otto A1 - Meyer, Rhonda C. A1 - Schmuths, Heike A1 - Hoffmann, Matthias H. A1 - Altmann, Thomas T1 - Evidence for a large-scale population structure of Arabidopsis thaliana from genome-wide single nucleotide polymorphism markers N2 - Population-based methods for the genetic mapping of adaptive traits and the analysis of natural selection require that the population structure and demographic history of a species are taken into account. We characterized geographic patterns of genetic variation in the model plant Arabidopsis thaliana by genotyping 115 genome-wide single nucleotide polymorphism (SNP) markers in 351 accessions from the whole species range using a matrix-assisted laser desorption/ionization time-of-flight assay, and by sequencing of nine unlinked short genomic regions in a subset of 64 accessions. The observed frequency distribution of SNPs is not consistent with a constant-size neutral model of sequence polymorphism due to an excess of rare polymorphisms. There is evidence for a significant population structure as indicated by differences in genetic diversity between geographic regions. Accessions from Central Asia have a low level of polymorphism and an increased level of genome-wide linkage disequilibrium (LD) relative to accessions from the Iberian Peninsula and Central Europe. Cluster analysis with the structure program grouped Eurasian accessions into K=6 clusters. Accessions from the Iberian Peninsula and from Central Asia constitute distinct populations, whereas Central and Eastern European accessions represent admixed populations in which genomes were reshuffled by historical recombination events. These patterns likely result from a rapid postglacial recolonization of Eurasia from glacial refugial populations. Our analyses suggest that mapping populations for association or LD mapping should be chosen from regional rather than a species-wide sample or identified genetically as sets of individuals with similar average genetic distances Y1 - 2006 UR - http://www.springerlink.com/content/d1683r7455648841/fulltext.html U6 - https://doi.org/10.1007/s00122-006-0212-7 ER - TY - JOUR A1 - Schelter, Björn A1 - Winterhalder, Matthias A1 - Dahlhaus, Rainer A1 - Kurths, Jürgen A1 - Timmer, Jens T1 - Partial phase synchronization for multivariate synchronizing systems N2 - Graphical models applying partial coherence to multivariate time series are a powerful tool to distinguish direct and indirect interdependencies in multivariate linear systems. We carry over the concept of graphical models and partialization analysis to phase signals of nonlinear synchronizing systems. This procedure leads to the partial phase synchronization index which generalizes a bivariate phase synchronization index to the multivariate case and reveals the coupling structure in multivariate synchronizing systems by differentiating direct and indirect interactions. This ensures that no false positive conclusions are drawn concerning the interaction structure in multivariate synchronizing systems. By application to the paradigmatic model of a coupled chaotic Roessler system, the power of the partial phase synchronization index is demonstrated Y1 - 2006 UR - http://prl.aps.org/abstract/PRL/v96/i20/e208103 U6 - https://doi.org/10.1103/Physrevlett.96.208103 ER - TY - JOUR A1 - Sanner, Helge T1 - Imperfect goods and labor markets, and the union wage gap N2 - Existing theoretical literature fails to explain satisfactorily the differences between the pay of workers who are covered by collective agreements and others who are not. This study aims at providing a model framework that is amenable to 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 Y1 - 2006 UR - http://www.springerlink.com/content/3w24p22662858503/fulltext.html U6 - https://doi.org/10.1007/s00148-005-0010-6 ER - TY - JOUR A1 - Saarimäki, Eetta A1 - Paajanen, Mika A1 - Savijärvi, Ann-Mari A1 - Minkkinen, Hannu A1 - Wegener, Michael A1 - Voronina, Olena A1 - Schulze, Robert A1 - Wirges, Werner A1 - Gerhard, Reimund T1 - Novel heat durable electromechanical film : processing for electromechanical and electret applications N2 - New ferroelectrets were developed on the basis of foams from cyclo-olefin polymers and copolymers. The results obtained on the cyclo-olefin polymer foam demonstrate a significant improvement of the service temperature for ferroelectret transducer materials. Suitable compounding and preparation led to cyclo-olefin ferroelectrets with an electromechanical activity of around 15 pC/N, which is thermally stable at least up to 110 degrees C. The properties in sensor and actuator applications are strongly dependent on the processing parameters related to film-making, sensor and actuator preparation, gas content and electric charging. The processing window for the film stretching was very narrow compared to the earlier developed polypropylene ferroelectrets. The film porosity, softness and thus the electromechanical activity are adjusted by gas-diffusion expansion. The activity of the electromechanically operating sensors and actuators was increased by stacking several layers of cellular cyclo-olefin film. For applications such as flat loudspeakers, the foamed films are tuned by tensioning them on a support frame. Correct tensioning was essential also for reducing the distortion levels. Y1 - 2006 ER - TY - JOUR A1 - Rullens, F A1 - Vuillaume, Pascal Y. A1 - Moussa, Alain A1 - Habib-Jiwan, Jean-Louis A1 - Laschewsky, André T1 - Ordered polyelectrolyte "Multilayers". 7. Hybrid films self-assembled from fluorescent and smectogenic poly(diallylammonium) salts and delaminated clay N2 - Homopolymers were prepared from diallylammonium monomers bearing 4-methylcoumarin and 4-cyanobiphenyl as fluorescent and mesogenic side groups, as well as their copolymers with diallyldimethylammonium chloride (DADMAC). Organic-inorganic hybrid films were electrostatically self-assembled via the layer-by-layer technique on silicon wafers and quartz plates from the chromophore-bearing polymers and an exfoliated synthetic hectorite. Photophysical studies performed in solution as well as in the self-assembled films demonstrated only a weak tendency for aggregation of the chromophores in the macromolecules. Moreover, assemblies made from the polymers carrying the cyanobiphenyl mesogen were found to exhibit a pronounced internal order Y1 - 2006 UR - http://pubs.acs.org/doi/full/10.1021/cm060209x U6 - https://doi.org/10.1021/Cm060209x ER - TY - JOUR A1 - Rullens, F A1 - Laschewsky, André A1 - Devillers, M T1 - Bulk and thin films of bismuth vanadates prepared from hybrid materials made from an organic polymer and inorganic salts N2 - A new precursor route for the preparation of bulk oxides and thin films of bismuth vanadates is proposed. The method involves the thermal treatment under air and mild conditions of hybrid organic-inorganic precursors, made from a zwitterionic salt-free polymer matrix and selected inorganic species. Monoclinic BiVO4 was obtained in the form of bulk oxide by calcination of the powdered homogeneous hybrid materials at 600 degrees C, from precursors containing Bi and V in stoichiometric amounts. In the same way, thermodiffractometry studies performed on a hybrid material exhibiting a Bi/ V molar ratio of 2 revealed that the ionic conductor gamma-Bi4V2O11 phase can be stabilized under very soft thermal conditions (300 degrees C). Additionally, thin films of yellow monoclinic BiVO4 were for the first time fabricated, by thermal treatment of the same hybrid polymeric precursors deposited on quartz substrates by spin coating, using a layer- by-layer technique. The presence of the target phase at the surface of the plates was confirmed by X-ray diffraction as well as UV-vis measurements Y1 - 2006 UR - http://pubs.acs.org/doi/full/10.1021/cm051516q U6 - https://doi.org/10.1021/Cm051516q ER - TY - JOUR A1 - Rufer, CE A1 - Kulling, Sabine E. T1 - Antioxidant activity of isoflavones and their major metabolites using different in vitro assays N2 - Isoflavone phytoestrogens found mainly in soybeans and clover are widely studied phytochemicals. Genistein and daidzein, the major isoflavones found in soy, have received the most attention. However, they undergo extensive metabolism in the intestine and the liver, which might affect their biological properties, e.g. their antioxidant capacities. Furthermore, the biological activities of other naturally occurring isoflavones, for instance, glycitein from soy or biochanin A from red clover, have not yet been studied in detail. The aim of this study was to investigate the antioxidant activities of six naturally occurring isoflavones and their corresponding oxidative and bacterial metabolites. The oxygen radical absorbance capacity assay as well as the in vitro oxidation of low density lipoproteins with the conjugated diene and the thiobarbituric acid reacting substances formation as end points were used. The oxidative metabolites of genistein and daidzein as well as equol exhibited the highest antioxidant activities in all three assays. With few exceptions, they were more effective than the positive controls quercetin and ascorbic acid. Formononetin, the 4'-O-methyl ether of daidzein, showed the lowest antioxidant property. Because the antioxidant efficacy of isoflavones as effective antioxidants is evident at concentrations well within the range found in the plasma of subjects consuming soy products, this biological activity could be of physiological relevance Y1 - 2006 UR - http://pubs.acs.org/doi/full/10.1021/jf053112o ER - TY - JOUR A1 - Rolfs, Martin A1 - Laubrock, Jochen A1 - Kliegl, Reinhold T1 - Shortening and prolongation of saccade latencies following microsaccades N2 - 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 could, thus, decrease saccade latencies. Second, microsaccades are likely to 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 would be expected after microsaccades. 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, mean saccadic reaction time in visual and memory trials was 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 the preparation of saccade motor programs Y1 - 2006 UR - http://www.springerlink.com/content/y67j226367352u28/fulltext.html U6 - https://doi.org/10.1007/s00221-005-0148-1 ER - TY - JOUR A1 - Maurer, Katrin A1 - Weyand, Anne A1 - Fischer, Markus A1 - Stöcklin, Jürg T1 - Old cultural traditions, in addition to land use and topography, are shaping plant diversity of grasslands in the Alps N2 - Socio-economically motivated land use changes are a major threat for species diversity of grasslands throughout the world. Here, we comprehensively explore how plant species diversity of grasslands in the species-rich cultural landscape of the Swiss Alps depends on recent land use changes, and, neglected in previous studies, on old cultural traditions. We studied diversity in 216 grassland parcels at three altitudinal levels in 12 villages of three cultural traditions (Romanic, Germanic, and Walser). In valleys of Romanic villages more different parcel types tended to occur than in those of Germanic and Walser villages, suggesting that socio-economic differences among cultural traditions still play a role in shaping landscape diversity. Moreover, at the village level, higher man-made landscape diversity was associated with higher plant species richness. All observed changes in land use reduced the farmers' workload. Plant species richness was lower in fertilized than in unfertilized parcels and in abandoned compared with used parcels. Grazing slightly reduced species richness compared with mowing among unfertilized parcels, while in fertilized parcels it had a positive influence. The highest species diversity was found in mown unfertilized subalpine grasslands. Nevertheless, moderate grazing of former meadows can be a valuable alternative to abandonment. We conclude that the ongoing changes in land use reduce plant species richness within parcels and at the landscape level. To preserve plant species diversity at the landscape level a high diversity of land use types has to be maintained. Y1 - 2006 UR - http://www.sciencedirect.com/science/journal/00063207 U6 - https://doi.org/10.1016/j.biocon.2006.01.005 SN - 0006-3207 ER - TY - JOUR A1 - Leimu, Roosa A1 - Mutikainen, Pia A1 - Koricheva, Julia A1 - Fischer, Markus T1 - How general are positive relationships between plant population size, fitness and genetic variation? N2 - 1 Relationships between plant population size, fitness and within-population genetic diversity are fundamental for plant ecology, evolution and conservation. We conducted meta-analyses of studies published between 1987 and 2005 to test whether these relationships are generally positive, whether they are sensitive to methodological differences among studies, whether they differ between species of different life span, mating system or rarity and whether they depend on the size ranges of the studied populations. 2 Mean correlations between population size, fitness and genetic variation were all significantly positive. The positive correlation between population size and female fitness tended to be stronger in field studies than in common garden studies, and the positive correlation between genetic variation and fitness was significantly stronger in DNA than in isoenzyme studies. 3 The strength and direction of correlations between population size, fitness and genetic variation were independent of plant life span and the size range of the studied populations. The mean correlations tended to be stronger for the rare species than for common species. 4 Expected heterozygosity, the number of alleles and the number or proportion of polymorphic loci significantly increased with population size, but the level of inbreeding F-IS was independent of population size. The positive relationship between population size and the number of alleles and the number or proportion of polymorphic loci was stronger in self- incompatible than in self-compatible species. Furthermore, fitness and genetic variation were positively correlated in self-incompatible species, but independent of each other in self-compatible species. 5 The close relationships between population size, genetic variation and fitness suggest that population size should always be taken into account in multipopulation studies of plant fitness or genetic variation. 6 The observed generality of the positive relationships between population size, plant fitness and genetic diversity implies that the negative effects of habitat fragmentation on plant fitness and genetic variation are common. Moreover, the stronger positive associations observed in self- incompatible species and to some degree in rare species, suggest that these species are most prone to the negative effects of habitat fragmentation Y1 - 2006 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0022-0477 U6 - https://doi.org/10.1111/j.1365-2745.2006.01150.x SN - 0022-0477 ER - TY - JOUR A1 - Laubrock, Jochen A1 - Kliegl, Reinhold A1 - Engbert, Ralf T1 - SWIFT explorations of age differences in eye movements during reading Y1 - 2006 UR - http://www.sciencedirect.com/science/journal/01497634 U6 - https://doi.org/10.1016/j.neubiorev.2006.06.013 SN - 0149-7634 ER - TY - JOUR A1 - Landa, Polina S. A1 - Ushakov, Vladimir A1 - Kurths, Jürgen T1 - Rigorous theory of stochastic resonance in overdamped bistable oscillators for weak signals JF - Chaos, solitons & fractals : applications in science and engineering N2 - The results of the theoretical consideration of stochastic resonance in overdamped bistable oscillators are given. These results are founded not on the model of two states as in [McNamara B, Wiesenfeld K. Theory of stochastic resonance. Phys Rev A 1989;39:4854-69], but on splitting of motion into regular and random and the rigorous solution of the Fokker-Planck equation for the random component. We show that this resonance is caused by a change, under the influence of noise, of the system's effective stiffness and damping factor contained in the equation for the regular component. For a certain value of the noise intensity the effective stiffness is minimal, and this fact causes non-monotonic change of the output signal amplitude as the noise intensity changes. It is important that the location of the minimum and its value depend essentially on the signal frequency. Y1 - 2006 UR - http://www.sciencedirect.com/science/journal/09600779 U6 - https://doi.org/10.1016/j.chaos.2005.08.116 SN - 0960-0779 VL - 30 IS - 3 SP - 574 EP - 578 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Küster, Yvonne A1 - Hetzel, Ralf A1 - Krbetschek, Matthias A1 - Tao, Mingxin T1 - Holocene loess sedimentation along the Qilian Shan (China) : significance for understanding the processes and timing of loess deposition N2 - We present optical ages for well preserved loess deposits along the Qilian Shan, a 500-km-long mountain belt forming the tectonically active northeastern margin of the Tibetan Plateau. Loess on tectonically controlled fill terraces along the Shiyou and Baiyong rivers was dated by applying the single-aliquot regeneration (SAR) technique to coarse-grained (90-160 mu m) quartz samples. Additional measurements on polymineralic fine-grained (5-10 mu m) samples were carried out to allow a comparison between various optical dating techniques currently in use. The results demonstrate that (i) loess accumulation started between 13 and 11 ka B.P., continuing to the present, (ii) mean loess accumulation rates range between similar to 9 and similar to 16 cm ka(-1), and (iii) Holocene loess is not restricted to certain sites only, but is a prevalent phenomenon along the Qilian Shan mountain front. The absence of loess deposits of Late Pleistocene age is a result of a combination of cold and dry climate conditions, strong winds, and the absence of a vegetation cover during the last glacial period. Only with the change to a warmer and moister climate at the onset of the Holocene did a plant cover develop, which acted as a dust trap, thus initiating the formation of loess. Y1 - 2006 UR - http://www.sciencedirect.com/science/journal/02773791 U6 - https://doi.org/10.1016/j.quascirev.2005.03.003 SN - 0277-3791 ER - TY - JOUR A1 - Kuhlmann, Sabine T1 - Local government reform between 'exogenous' and 'endogenous' driving forces : Institution building in the city of Paris N2 - The article attempts to analyse institutional reforms in the multi-level system of the French capital city. The key questions are the developments in central-local relations and what factors influenced these changes over the last century. The author seeks to identify 'critical junctures' in institutional development and explore their impact on the relationships between state and municipality on the one hand and between upper and lower tiers of city- government on the other. Looking at institution building in Paris as the dependent variable the article takes a primarily institutionalist approach in identifying the relevant factors which explain local government reform in the capital city ('what shapes institutions?') Y1 - 2006 UR - http://www.metapress.com/link.asp?id=104725 U6 - https://doi.org/10.1080/14719030500518790 SN - 1471-9037 ER - TY - JOUR A1 - Kröner, Alfred A1 - Wilde, Simon A. A1 - Zhao, Guochun A1 - O'Brien, Patrick J. A1 - Sun, Min A1 - Liu, Dun Yi A1 - Wan, Yusheng A1 - Liu, S. W. A1 - Guo, Jianbin H. T1 - Zircon geochronology and metamorphic evolution of mafic dykes in the Hengshan Complex of northern China: Evidence for late Palaeoproterozoic extension and subsequent high-pressure metamorphism in the North China Craton N2 - Magmatic and metamorphic zircons have been dated from ductilely deformed gabbroic dykes defining a dyke swarm and signifying crustal extension in the northern part of the Hengshan Complex of the North China Craton, These dykes now occur as boudins and deformed sheets within migmatitic tonalitic, trondhjemitic, granodioritic and granitic gneisses and are conspicuous due to relics of high-pressure granulite or even former eclogite facies garnet + pyroxene-bearing assemblages. SHRIMP ages for magmatic zircons from two dykes reflect the time of dyke emplacement at similar to 1915 Ma, whereas metamorphic zircons dated by both SHRIMP and evaporation techniques are consistently in the range 1848-1888 Ma. The Youngest granitoid gneiss yet dated in the Hengshan has an emplacement age of 18 2 17 Ma. These results complement recent geochronological studies from the neighbouring Wutai and Fuping Complexes, to the SE of the Hengshan, showing that a crustal extension event Occurred in the late Palaeoproterozoic. This preceded a major high-pressure collision- type metamorphic event in the central part of the North China Craton that occurred in the Palaeoproterozoic and not in the late Archaean as previously thought. Our data support recent suggestions that the North China Craton experienced a major, craton-wide orogenic event in the late Palaeoproterozoic after which it became cratonized and acted as a stable block. Y1 - 2006 U6 - https://doi.org/10.1016/j.precamres.2006.01.008 SN - 0301-9268 ER - TY - JOUR A1 - Kreft, Oliver A1 - Georgieva, Radostina A1 - Bäumler, Hans A1 - Steup, Martin A1 - Müller-Röber, Bernd A1 - Sukhorukov, Gleb B. A1 - Möhwald, Helmuth T1 - Red blood cell templated polyelectrolyte capsules : a novel vehicle for the stable encapsulation of DNA and proteins N2 - A novel method for the encapsulation of biomacromolecules, such as nucleic acids and proteins, into polyelectrolyte microcapsules is described. Fluorescence-labelled double-stranded DNA and human serum albumin (HSA) are used as model substances for encapsulation in hollow microcapsules templated on human erythrocytes. The encapsulation procedure involves an intermediate drying C, step. The accumulation of DNA and HSA in the capsules is observed by confocal laser scanning microscopy, UV spectroscopy, and flourimetry. The mechanism of encapsulation is discussed Y1 - 2006 UR - http://www3.interscience.wiley.com/cgi-bin/jhome/10003270 U6 - https://doi.org/10.1002/marc.200500777 SN - 1022-1336 ER -