TY - JOUR A1 - Meckelmann, Viola A1 - Pfeifer, Caroline A1 - Rauh, Hellgard T1 - Family relationships in childhood, pubertal timing, and subsequent reproductive strategies among adolescents JF - South African journal of psychology N2 - The evolutionary theory of socialization of Belsky, Steinberg, and Draper was investigated on the empirical basis of a longitudinal sample of 26 adolescent girls and boys who were born in Berlin during German reunification, as well as their mothers. Consistent with the theory, pubertal timing of the girls (but not of the boys) was predicted by the quality of parental relations in childhood, and pubertal timing of the girls (but not of the boys) was a significant predictor of the age at first intercourse. The results suggest that there are different developmental pathways for girls and boys with respect to the predictions of the evolutionary theory of socialization of Belsky et al. The findings also support the hypothesis that early onset of reproduction and frequent reproduction may be two different aspects of a quantitative reproductive strategy. KW - Adolescence KW - childhood KW - family relations KW - pubertal timing KW - puberty KW - reproductive strategies Y1 - 2013 U6 - https://doi.org/10.1177/0081246312474408 SN - 0081-2463 VL - 43 IS - 1 SP - 22 EP - 33 PB - Sage Publ. CY - London ER - TY - JOUR A1 - Westendorf, Christian A1 - Negrete, Jose A1 - Bae, Albert J. A1 - Sandmann, Rabea A1 - Bodenschatz, Eberhard A1 - Beta, Carsten T1 - Actin cytoskeleton of chemotactic amoebae operates close to the onset of oscillations JF - Proceedings of the National Academy of Sciences of the United States of America N2 - The rapid reorganization of the actin cytoskeleton in response to external stimuli is an essential property of many motile eukaryotic cells. Here, we report evidence that the actin machinery of chemotactic Dictyostelium cells operates close to an oscillatory instability. When averaging the actin response of many cells to a short pulse of the chemoattractant cAMP, we observed a transient accumulation of cortical actin reminiscent of a damped oscillation. At the single-cell level, however, the response dynamics ranged from short, strongly damped responses to slowly decaying, weakly damped oscillations. Furthermore, in a small subpopulation, we observed self-sustained oscillations in the cortical F-actin concentration. To substantiate that an oscillatory mechanism governs the actin dynamics in these cells, we systematically exposed a large number of cells to periodic pulse trains of different frequencies. Our results indicate a resonance peak at a stimulation period of around 20 s. We propose a delayed feedback model that explains our experimental findings based on a time-delay in the regulatory network of the actin system. To test the model, we performed stimulation experiments with cells that express GFP-tagged fusion proteins of Coronin and actin-interacting protein 1, as well as knockout mutants that lack Coronin and actin-interacting protein 1. These actin-binding proteins enhance the disassembly of actin filaments and thus allow us to estimate the delay time in the regulatory feedback loop. Based on this independent estimate, our model predicts an intrinsic period of 20 s, which agrees with the resonance observed in our periodic stimulation experiments. KW - Dictyostelium discoideum KW - microfluidics KW - caged cAMP KW - delay-differential equation Y1 - 2013 U6 - https://doi.org/10.1073/pnas.1216629110 SN - 0027-8424 VL - 110 IS - 10 SP - 3853 EP - 3858 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Harma, Harri A1 - Pihlasalo, Sari A1 - Cywinski, Piotr J. A1 - Mikkonen, Piia A1 - Hammann, Tommy A1 - Löhmannsröben, Hans-Gerd A1 - Hanninen, Pekka T1 - Protein quantification using resonance energy transfer between donor nanoparticles and acceptor quantum dots JF - Analytical chemistry N2 - A homogeneous time-resolved luminescence resonance energy transfer (TR-LRET) assay has been developed to quantify proteins. The competitive assay is based on resonance energy transfer (RET) between two luminescent nanosized particles. Polystyrene nanoparticles loaded with Eu3+ chelates (EuNPs) act as donors, while protein-coated quantum dots (QDs), either CdSe/ZnS emitting at 655 nm (QD655-strep) or CdSeTe/ZnS with emission wavelength at 705 nm (QD705-strep), are acceptors. In the absence of analyte protein, in our case bovine serum albumin (BSA), the protein-coated QDs bind nonspecifically to the EuNPs, leading to RET. In the presence of analyte proteins, the binding of the QDs to the EuNPs is prevented and the RET signal decreases. RET from the EuNPs to the QDs was confirmed and characterized with steady-state and time-resolved luminescence spectroscopy. In accordance with the Forster theory, the approximate average donor acceptor distance is around 15 nm at RET efficiencies, equal to 15% for QD655 and 13% for QD705 acceptor, respectively. The limits of detection are below 10 ng of BSA with less than a 10% average coefficient of variation. The assay sensitivity is improved, when compared to the most sensitive commercial methods. The presented mix-and-measure method has potential to be implemented into routine protein quantification in biological laboratories. Y1 - 2013 U6 - https://doi.org/10.1021/ac303586n SN - 0003-2700 VL - 85 IS - 5 SP - 2921 EP - 2926 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Julich-Gruner, Konstanze K. A1 - Löwenberg, Candy A1 - Neffe, Axel T. A1 - Behl, Marc A1 - Lendlein, Andreas T1 - Recent trends in the chemistry of shape-memory polymers JF - Macromolecular chemistry and physics N2 - Shape-memory polymers (SMPs) are stimuli-sensitive materials capable of performing complex movements on demand, which makes them interesting candidates for various applications, for example, in biomedicine or aerospace. This trend article highlights current approaches in the chemistry of SMPs, such as tailored segment chemistry to integrate additional functions and novel synthetic routes toward permanent and temporary netpoints. Multiphase polymer networks and multimaterial systems illustrate that SMPs can be constructed as a modular system of different building blocks and netpoints. Future developments are aiming at multifunctional and multistimuli-sensitive SMPs. KW - multifunctional polymers KW - networks KW - shape-memory polymers KW - stimuli-sensitive polymers KW - triple-shape effect Y1 - 2013 U6 - https://doi.org/10.1002/macp.201200607 SN - 1022-1352 VL - 214 IS - 5 SP - 527 EP - 536 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Beye, Martin A1 - Föhlisch, Alexander T1 - Soft X-ray probes of ultrafast dynamics for heterogeneous catalysis JF - Chemical physics : a journal devoted to experimental and theoretical research involving problems of both a chemical and physical nature N2 - Soft X-ray spectroscopy is one of the best tools to directly address the electronic structure, the driving force of chemical reactions. It enables selective studies on sample surfaces to single out reaction centers in heterogeneous catalytic reactions. With core-hole clock methods, specific dynamics are related to the femtosecond life time of a core-hole. Typically, this method is used with photoemission spectroscopy, but advancements in soft X-ray emission techniques render more specific studies possible. With the advent of bright femtosecond pulsed soft X-ray sources, highly selective pump-probe X-ray emission studies are enabled with temporal resolutions down to tens of femtoseconds. This finally allows to study dynamics in the electronic structure of adsorbed reaction centers on the whole range of relevant time scales - closing the gap between kinetic soft X-ray studies and the atto- to femtosecond core-hole clock techniques. KW - Core-hole clock KW - Resonant inelastic X-ray scattering KW - Ultrafast surface science KW - Photoelectron spectroscopy Y1 - 2013 U6 - https://doi.org/10.1016/j.chemphys.2012.03.023 SN - 0301-0104 SN - 1873-4421 VL - 414 IS - 5 SP - 130 EP - 138 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Jechow, Andreas A1 - Norton, B. G. A1 - Händel, S. A1 - Blums, V. A1 - Streed, E. W. A1 - Kielpinski, D. T1 - Controllable optical phase shift over one radian from a single isolated atom JF - Physical review letters N2 - Fundamental optics such as lenses and prisms work by applying phase shifts of several radians to incoming light, and rapid control of such phase shifts is crucial to telecommunications. However, large, controllable optical phase shifts have remained elusive for isolated quantum systems. We have used a single trapped atomic ion to induce and measure a large optical phase shift of 1.3 +/- 0.1 radians in light scattered by the atom. Spatial interferometry between the scattered light and unscattered illumination light enables us to isolate the phase shift in the scattered component. The phase shift achieves the maximum value allowed by atomic theory over the accessible range of laser frequencies, pointing out new opportunities in microscopy and nanophotonics. Single-atom phase shifts of this magnitude open up new quantum information protocols, in particular long-range quantum phase-shift-keying cryptography. DOI: 10.1103/PhysRevLett.110.113605 Y1 - 2013 U6 - https://doi.org/10.1103/PhysRevLett.110.113605 SN - 0031-9007 VL - 110 IS - 11 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Osterloh, Lukas A1 - Böckmann, Christine A1 - Nicolae, Doina A1 - Nemuc, Anca T1 - Regularized inversion of microphysical atmospheric particle parameters - theory and application JF - Journal of computational physics N2 - Retrieving the distribution of aerosols in the atmosphere via remote sensing techniques is a highly complex task that requires dealing with a wide range of different problems stemming both from Physics and Mathematics. We focus on retrieving this distribution from multi-wavelength lidar data for aerosol ensembles consisting of spherical particles via an iterative regularization technique. The optical efficiencies for spherical scatterers are examined to account for the behavior of the underlying integral equation. The ill-posedness of the problem and the conditioning of the discretized problem are analyzed. Some critical points in the model, like the assumed wavelength-independence of the refractive index and the fixed grid of investigated refractive indices, are studied with regard to their expected impact on the regularized solution. A new Monte-Carlo type method is proposed for retrieval of the refractive index. To validate the results, the developed algorithm is applied to two measurement cases of burning biomass gained from multi-wavelength Raman lidar. KW - Inverse ill-posed problem KW - Regularization KW - Lidar remote sensing KW - Microphysical particle properties Y1 - 2013 U6 - https://doi.org/10.1016/j.jcp.2012.11.040 SN - 0021-9991 VL - 237 IS - 11 SP - 79 EP - 94 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Lemke, Karina A1 - Prietzel, Claudia Christina A1 - Koetz, Joachim T1 - Fluorescent gold clusters synthesized in a poly(ethyleneimine) modified reverse microemulsion JF - Journal of colloid and interface science N2 - This paper is focused on the formation of gold clusters in a tailor-made polyelectrolyte-modified reverse microemulsion using poly(ethyleneimine) (PEI) as a cationic polyelectrolyte. PEI incorporated into a ternary w/o microemulsion consisting of water/heptanol/zwitterionic surfactant 3-(N,N-dimethyl-dodecylammonio)-propanesulfonate (SB) acts as a reducing and stabilizing agent and shows an additional template effect. The nanoparticle synthesis is performed by a simple mixing of two microemulsions, one containing the PEI and the other one containing the gold chloride precursor. UV-vis measurements in the microemulsion show two pronounced absorption maxima, one at 360 nm and the other one at 520 nm, indicating two particle fractions. The absorption maximum at 360 nm in combination to the unique fluorescence properties indicate the formation of gold clusters. After a complete solvent evaporation the redispersed nanoparticles have been characterized by using UV-vis and fluorescence spectroscopy, in combination to dynamic light scattering and transmission electron microscopy (TEM). In addition to the gold nanoparticle fraction (>5 nm) the fluorescent gold cluster fraction (<2 nm) can be redispersed without particle aggregation. By means of asymmetric flow field flow fractionation (AF-FFF) two different cluster fractions with particle diameter (<2 nm) can be identified. KW - Microemulsion KW - Gold cluster KW - Field flow fractionation KW - Polymer capped gold nanoparticles Y1 - 2013 U6 - https://doi.org/10.1016/j.jcis.2012.11.057 SN - 0021-9797 VL - 394 SP - 141 EP - 146 PB - Elsevier CY - San Diego ER - TY - JOUR A1 - Dell'Angela, M. A1 - Anniyev, Toyli A1 - Beye, Martin A1 - Coffee, Ryan A1 - Föhlisch, Alexander A1 - Gladh, J. A1 - Katayama, T. A1 - Kaya, S. A1 - Krupin, O. A1 - LaRue, J. A1 - Mogelhoj, A. A1 - Nordlund, D. A1 - Norskov, J. K. A1 - Oberg, H. A1 - Ogasawara, H. A1 - Ostrom, H. A1 - Pettersson, Lars G. M. A1 - Schlotter, W. F. A1 - Sellberg, J. A. A1 - Sorgenfrei, Nomi A1 - Turner, J. J. A1 - Wolf, M. A1 - Wurth, W. A1 - Nilsson, A. T1 - Real-time observation of surface bond breaking with an X-ray Laser JF - Science N2 - We used the Linac Coherent Light Source free-electron x-ray laser to probe the electronic structure of CO molecules as their chemisorption state on Ru(0001) changes upon exciting the substrate by using a femtosecond optical laser pulse. We observed electronic structure changes that are consistent with a weakening of the CO interaction with the substrate but without notable desorption. A large fraction of the molecules (30%) was trapped in a transient precursor state that would precede desorption. We calculated the free energy of the molecule as a function of the desorption reaction coordinate using density functional theory, including van der Waals interactions. Two distinct adsorption wells-chemisorbed and precursor state separated by an entropy barrier-explain the anomalously high prefactors often observed in desorption of molecules from metals. Y1 - 2013 U6 - https://doi.org/10.1126/science.1231711 SN - 0036-8075 VL - 339 IS - 6125 SP - 1302 EP - 1305 PB - American Assoc. for the Advancement of Science CY - Washington ER - TY - JOUR A1 - Kleinpeter, Erich A1 - Werner, Peter A1 - Koch, Andreas T1 - Push-pull allenes-conjugation, (anti)aromaticity and quantification of the push-pull character JF - Tetrahedron N2 - Structures, H-1/C-13 chemical shifts, and pi electron distribution/conjugation of an experimentally available and theoretically completed set of push-pull allenes Acc(2)C=C=CDon(2) (Acc=F, CHO, CF3, C N; Don=t-Bu, OMe, OEt, SMe, SEt, NCH2R) have been computed at the OFT level of theory. Both orthogonal linear and orthogonal bent structures have been obtained. In the latter case the push-pull character could be quantified by the quotient method. The C-13 chemical shift of the central allene carbon atom C-2 and chemical shift differences Delta delta(C-1, C-2) and Delta delta(C-2, C-3) of allene carbon atoms proved to be a quantitative alternative. TSNMRS of ring-closed push-pull allenes have been computed in addition and were employed to identify polar, carbene-like and carbone-like canonical structures of these molecules. KW - Push-pull allenes KW - Push-pull character KW - C-13 NMR spectroscopy KW - Quotient method KW - TSNMRS KW - ICSS KW - Aromaticity Y1 - 2013 U6 - https://doi.org/10.1016/j.tet.2013.01.027 SN - 0040-4020 VL - 69 IS - 11 SP - 2436 EP - 2445 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Pohl, Martin A1 - Eichler, David T1 - Understanding TeV-band cosmic-ray anistropy JF - The astrophysical journal : an international review of spectroscopy and astronomical physics N2 - We investigate the temporal and spectral correlations between flux and anisotropy fluctuations of TeV-band cosmic rays in light of recent data taken with IceCube. We find that for a conventional distribution of cosmic-ray sources, the dipole anisotropy is higher than observed, even if source discreteness is taken into account. Moreover, even for a shallow distribution of galactic cosmic-ray sources and a reacceleration model, fluctuations arising from source discreteness provide a probability only of the order of 10% that the cosmic-ray anisotropy limits of the recent IceCube analysis are met. This probability estimate is nearly independent of the exact choice of source rate, but generous for a large halo size. The location of the intensity maximum far from the Galactic Center is naturally reproduced. KW - cosmic rays Y1 - 2013 U6 - https://doi.org/10.1088/0004-637X/766/1/4 SN - 0004-637X VL - 766 IS - 1 PB - IOP Publ. Ltd. CY - Bristol ER - TY - JOUR A1 - Taft, Linda A1 - Wiechert, Uwe A1 - Zhang, Hucai A1 - Lei, Guoliang A1 - Mischke, Steffen A1 - Plessen, Birgit A1 - Weynell, Marc A1 - Winkler, Andreas A1 - Riedel, Frank T1 - Oxygen and carbon isotope patterns archived in shells of the aquatic gastropod Radix - hydrologic and climatic signals across the Tibetan Plateau in sub-monthly resolution JF - Quaternary international : the journal of the International Union for Quaternary Research N2 - The Tibetan Plateau (TP), including its surrounding mountain ranges, represents the largest store of ice outside the polar regions. It hosts numerous lakes as well as the head waters of major Asian rivers, on which billions of people depend, and it is particularly sensitive to climate change. The moisture transport to the TP is controlled by the Indian and Pacific monsoon and the Westerlies. Understanding the evolution of the interaction of these circulation systems requires studies on climate archives in different spatial and temporal contexts. The objective of this study is to learn more about the interannual variability of precipitation patterns across the TP and how different hydrologic systems react to different climatic factors. Aragonite shells of the aquatic gastropod Radix, which is widely distributed in the region, may represent suitable archives for inferring hydrologic and climatic signals in particularly high resolution. Therefore, sclerochronological studies of delta O-18 and delta C-13 ratios in Radix shells from seven lakes were conducted, each representing a different hydrologic and climatic setting, on a transect from the Pamirs across the TP. The shell patterns exhibit an increasing influence of precipitation and a decreasing influence of evaporation on the isotope compositions from west to east. delta O-18 values of shells from lakes on the eastern and central TP (Donggi Cona, Yamdrok Yumco, Tarab Co) mirror monsoon signals, indicated by more negative values and higher variabilities compared to the more western lakes (Karakul, Bangong/Nyak, Manasarovar). In Yadang Co, located on the central southern TP, the monsoon rains did not reach the lake in the sampling year, although it is located in a region which is usually affected by monsoon circulation. The delta O-18 values are used to differentiate the annual hydrological cycle into ice cover period, melt water period, precipitation period and evaporation period. delta C-13 compositions in the shells particularly depend on specific habitats, which vary in biological productivity and in carbon sources. delta O-18 and delta C-13 patterns show a positive covariance in shells originating from large closed basins. The results show that Radix shells mirror general climatic differences between the seven lake regions. These differences reflect both regional and local climate signals in sub-seasonal resolution, without noticeable dependence on the particular lake system. Y1 - 2013 U6 - https://doi.org/10.1016/j.quaint.2012.10.031 SN - 1040-6182 VL - 290 IS - 1 SP - 282 EP - 298 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Blomeyer, Dorothea A1 - Buchmann, Arlette F. A1 - Lascorz, Jesus A1 - Zimmermann, Ulrich S. A1 - Esser, Günter A1 - Desrivieres, Sylvane A1 - Schmidt, Martin H. A1 - Banaschewski, Tobias A1 - Schumann, Gunter A1 - Laucht, Manfred T1 - Association of PER2 genotype and stressful life events with alcohol drinking in young adults JF - PLoS one N2 - Background: Clock genes govern circadian rhythms and shape the effect of alcohol use on the physiological system. Exposure to severe negative life events is related to both heavy drinking and disturbed circadian rhythmicity. The aim of this study was 1) to extend previous findings suggesting an association of a haplotype tagging single nucleotide polymorphism of PER2 gene with drinking patterns, and 2) to examine a possible role for an interaction of this gene with life stress in hazardous drinking. Methods: Data were collected as part of an epidemiological cohort study on the outcome of early risk factors followed since birth. At age 19 years, 268 young adults (126 males, 142 females) were genotyped for PER2 rs56013859 and were administered a 45-day alcohol timeline follow-back interview and the Alcohol Use Disorders Identification Test (AUDIT). Life stress was assessed as the number of severe negative life events during the past four years reported in a questionnaire and validated by interview. Results: Individuals with the minor G allele of rs56013859 were found to be less engaged in alcohol use, drinking at only 72% of the days compared to homozygotes for the major A allele. Moreover, among regular drinkers, a gene x environment interaction emerged (p = .020). While no effects of genotype appeared under conditions of low stress, carriers of the G allele exhibited less hazardous drinking than those homozygous for the A allele when exposed to high stress. Conclusions: These findings may suggest a role of the circadian rhythm gene PER2 in both the drinking patterns of young adults and in moderating the impact of severe life stress on hazardous drinking in experienced alcohol users. However, in light of the likely burden of multiple tests, the nature of the measures used and the nominal evidence of interaction, replication is needed before drawing firm conclusions. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0059136 SN - 1932-6203 VL - 8 IS - 3 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Kuptsov, Pavel V. A1 - Kuznetsov, Sergey P. A1 - Pikovskij, Arkadij T1 - Hyperbolic chaos at blinking coupling of noisy oscillators JF - Physical review : E, Statistical, nonlinear and soft matter physics N2 - We study an ensemble of identical noisy phase oscillators with a blinking mean-field coupling, where onecluster and two-cluster synchronous states alternate. In the thermodynamic limit the population is described by a nonlinear Fokker-Planck equation. We show that the dynamics of the order parameters demonstrates hyperbolic chaos. The chaoticity manifests itself in phases of the complex mean field, which obey a strongly chaotic Bernoulli map. Hyperbolicity is confirmed by numerical tests based on the calculations of relevant invariant Lyapunov vectors and Lyapunov exponents. We show how the chaotic dynamics of the phases is slightly smeared by finite-size fluctuations. DOI: 10.1103/PhysRevE.87.032912 Y1 - 2013 U6 - https://doi.org/10.1103/PhysRevE.87.032912 SN - 1539-3755 VL - 87 IS - 3 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Komarov, Maxim A1 - Pikovskij, Arkadij T1 - Dynamics of multifrequency oscillator communities JF - Physical review letters N2 - We consider a generalization of the Kuramoto model of coupled oscillators to the situation where communities of oscillators having essentially different natural frequencies interact. General equations describing possible resonances between the communities' frequencies are derived. The simplest situation of three resonantly interacting groups is analyzed in detail. We find conditions for the mutual coupling to promote or suppress synchrony in individual populations and present examples where the interaction between communities leads to their synchrony or to a partially asynchronous state or to a chaotic dynamics of order parameters. DOI: 10.1103/PhysRevLett.110.134101 Y1 - 2013 U6 - https://doi.org/10.1103/PhysRevLett.110.134101 SN - 0031-9007 VL - 110 IS - 13 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Pingel, P. A1 - Neher, Dieter T1 - Comprehensive picture of p-type doping of P3HT with the molecular acceptor F(4)TCNQ JF - Physical review : B, Condensed matter and materials physics N2 - By means of optical spectroscopy, Kelvin probe, and conductivity measurements, we study the p-type doping of the donor polymer poly(3-hexylthiophene), P3HT, with the molecular acceptor tetrafluorotetracyanoquin-odimethane, F(4)TCNQ, covering a broad range of molar doping ratios from the ppm to the percent regime. Thorough quantitative analysis of the specific near-infrared absorption bands of ionized F(4)TCNQ reveals that almost every F(4)TCNQ dopant undergoes integer charge transfer with a P3HT site. However, only about 5% of these charge carrier pairs are found to dissociate and contribute a free hole for electrical conduction. The nonlinear behavior of the conductivity on doping ratio is rationalized by a numerical mobility model that accounts for the broadening of the energetic distribution of transport sites by the Coulomb potentials of ionized F(4)TCNQ dopants. DOI: 10.1103/PhysRevB.87.115209 Y1 - 2013 U6 - https://doi.org/10.1103/PhysRevB.87.115209 SN - 1098-0121 VL - 87 IS - 11 PB - American Physical Society CY - College Park ER - TY - JOUR A1 - Voss, Björn A1 - Bolhuis, Henk A1 - Fewer, David P. A1 - Kopf, Matthias A1 - Möke, Fred A1 - Haas, Fabian A1 - El-Shehawy, Rehab A1 - Hayes, Paul A1 - Bergman, Birgitta A1 - Sivonen, Kaarina A1 - Dittmann-Thünemann, Elke A1 - Scanlan, Dave J. A1 - Hagemann, Martin A1 - Stal, Lucas J. A1 - Hess, Wolfgang R. T1 - Insights into the physiology and ecology of the brackish-water-adapted cyanobacterium nodularia spumigena CCY9414 based on a genome-transcriptome analysis JF - PLoS one N2 - Nodularia spumigena is a filamentous diazotrophic cyanobacterium that dominates the annual late summer cyanobacterial blooms in the Baltic Sea. But N. spumigena also is common in brackish water bodies worldwide, suggesting special adaptation allowing it to thrive at moderate salinities. A draft genome analysis of N. spumigena sp. CCY9414 yielded a single scaffold of 5,462,271 nucleotides in length on which genes for 5,294 proteins were annotated. A subsequent strand-specific transcriptome analysis identified more than 6,000 putative transcriptional start sites (TSS). Orphan TSSs located in intergenic regions led us to predict 764 non-coding RNAs, among them 70 copies of a possible retrotransposon and several potential RNA regulators, some of which are also present in other N2-fixing cyanobacteria. Approximately 4% of the total coding capacity is devoted to the production of secondary metabolites, among them the potent hepatotoxin nodularin, the linear spumigin and the cyclic nodulapeptin. The transcriptional complexity associated with genes involved in nitrogen fixation and heterocyst differentiation is considerably smaller compared to other Nostocales. In contrast, sophisticated systems exist for the uptake and assimilation of iron and phosphorus compounds, for the synthesis of compatible solutes, and for the formation of gas vesicles, required for the active control of buoyancy. Hence, the annotation and interpretation of this sequence provides a vast array of clues into the genomic underpinnings of the physiology of this cyanobacterium and indicates in particular a competitive edge of N. spumigena in nutrient-limited brackish water ecosystems. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0060224 SN - 1932-6203 VL - 8 IS - 3 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Karpuz, Eylem Guzel A1 - Cevik, Ahmet Sinan A1 - Koppitz, Jörg A1 - Cangul, Ismail Naci T1 - Some fixed-point results on (generalized) Bruck-Reilly *-extensions of monoids JF - Fixed point theory and applications N2 - In this paper, we determine necessary and sufficient conditions for Bruck-Reilly and generalized Bruck-Reilly *-extensions of arbitrary monoids to be regular, coregular and strongly pi-inverse. These semigroup classes have applications in various field of mathematics, such as matrix theory, discrete mathematics and p-adic analysis (especially in operator theory). In addition, while regularity and coregularity have so many applications in the meaning of boundaries (again in operator theory), inverse monoids and Bruck-Reilly extensions contain a mixture fixed-point results of algebra, topology and geometry within the purposes of this journal. KW - Bruck-Reilly extension KW - generalized Bruck-Reilly *-extension KW - pi-inverse monoid KW - regular monoid Y1 - 2013 U6 - https://doi.org/10.1186/1687-1812-2013-78 SN - 1687-1812 IS - 3 PB - Springer CY - Cham ER - TY - JOUR A1 - Costa, Alexandre Cunha A1 - Förster, Saskia A1 - de Araujo, Jose Carlos A1 - Bronstert, Axel T1 - Analysis of channel transmission losses in a dryland river reach in north-eastern Brazil using streamflow series, groundwater level series and multi-temporal satellite data JF - Hydrological processes N2 - Scarcity of hydrological data, especially streamflow discharge and groundwater level series, restricts the understanding of channel transmission losses (TL) in drylands. Furthermore, the lack of information on spatial river dynamics encompasses high uncertainty on TL analysis in large rivers. The objective of this study was to combine the information from streamflow and groundwater level series with multi-temporal satellite data to derive a hydrological concept of TL for a reach of the Middle Jaguaribe River (MJR) in semi-arid north-eastern Brazil. Based on this analysis, we proposed strategies for its modelling and simulation. TL take place in an alluvium, where river and groundwater can be considered to be hydraulically connected. Most losses certainly infiltrated only through streambed and levees and not through the flood plains, as could be shown by satellite image analysis. TL events whose input river flows were smaller than a threshold did not reach the outlet of the MJR. TL events whose input flows were higher than this threshold reached the outlet losing on average 30% of their input. During the dry seasons (DS) and at the beginning of rainy seasons (DS/BRS), no river flow is expected for pre-events, and events have vertical infiltration into the alluvium. At the middle and the end of the rainy seasons (MRS/ERS), river flow sustained by base flow occurs before/after events, and lateral infiltration into the alluvium plays a major role. Thus, the MJR shifts from being a losing river at DS/BRS to become a losing/gaining (mostly losing) river at MRS/ERS. A model of this system has to include the coupling of river and groundwater flow processes linked by a leakage approach. KW - channel transmission losses KW - multi-temporal RapidEye satellite data KW - semi-arid hydrology KW - north-eastern Brazil KW - dryland rivers KW - riveraquifer interaction Y1 - 2013 U6 - https://doi.org/10.1002/hyp.9243 SN - 1099-1085 VL - 27 IS - 7 SP - 1046 EP - 1060 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Dodoo, Samuel A1 - Balzer, Bizan N. A1 - Hugel, Thorsten A1 - Laschewsky, André A1 - von Klitzing, Regine T1 - Effect of ionic strength and layer number on swelling of polyelectrolyte multilayers in water vapour JF - Soft materials N2 - The swelling behavior of polyelectrolyte multilayers (PEMs) of poly(sodium-4 styrene sulfonate) (PSS) and poly(diallyl dimethyl ammonium chloride) (PDADMAC) prepared from aqueous solution of 0.1 M and 0.5 M NaCl are investigated by ellipsometry and Atomic Force Microscopy (AFM). From 1 double-layer up to 4 double-layers of 0.1 M NaCl, the amount of swelling water in the PEMs decreases with increasing number of adsorbed double layers due to an increase in polyelectrolyte density as a result of the attraction between the positively charged outermost PDADMAC layer and the Si substrate. From 6 double layers to 30 double layers, the attraction is reduced due to a much larger distance between substrate and outermost layer leading to a much lower polyelectrolyte density and higher swelling water. In PEMs prepared from aqueous solution of 0.5 M NaCl, the amount of water constantly increases which is related to a monotonically decreasing polyelectrolyte density with increasing number of polyelectrolyte layers. Studies of the surface topology also indicate a transition from a more substrate affected interphase behavior to a continuum properties of the polyelectrolyte multilayers. The threshold for the transition from interphase to continuum behavior depends on the preparation conditions of the PEM. KW - Continuum properties KW - Interphase behavior KW - Ionic strength KW - Multilayers KW - Polyelectrolytes KW - Substrate effect KW - Swelling behavior KW - Threshold KW - Water vapor Y1 - 2013 U6 - https://doi.org/10.1080/1539445X.2011.607203 SN - 1539-445X VL - 11 IS - 2 SP - 157 EP - 164 PB - Taylor & Francis Group CY - Philadelphia ER - TY - JOUR A1 - Andres, Dorothee A1 - Gohlke, Ulrich A1 - Bröker, Nina Kristin A1 - Schulze, Stefan A1 - Rabsch, Wolfgang A1 - Heinemann, Udo A1 - Barbirz, Stefanie A1 - Seckler, Robert T1 - An essential serotype recognition pocket on phage P22 tailspike protein forces Salmonella enterica serovar Paratyphi A O-antigen fragments to bind as nonsolution conformers JF - Glycobiology N2 - Bacteriophage P22 recognizes O-antigen polysaccharides of Salmonella enterica subsp. enterica (S.) with its tailspike protein (TSP). In the serovars S. Typhimurium, S. Enteritidis, and S. Paratyphi A, the tetrasaccharide repeat units of the respective O-antigens consist of an identical main chain trisaccharide but different 3,6-dideoxyhexose substituents. Here, the epimers abequose, tyvelose and paratose determine the specific serotype. P22 TSP recognizes O-antigen octasaccharides in an extended binding site with a single 3,6-dideoxyhexose binding pocket. We have isolated S. Paratyphi A octasaccharides which were not available previously and determined the crystal structure of their complex with P22 TSP. We discuss our data together with crystal structures of complexes with S. Typhimurium and S. Enteritidis octasaccharides determined earlier. Isothermal titration calorimetry showed that S. Paratyphi A octasaccharide binds P22 TSP less tightly, with a difference in binding free energy of similar to 7 kJ mol(-1) at 20 degrees C compared with S. Typhimurium and S. Enteritidis octasaccharides. Individual protein-carbohydrate contacts were probed by amino acid replacements showing that the dideoxyhexose pocket contributes to binding of all three serotypes. However, S. Paratyphi A octasaccharides bind in a conformation with an energetically unfavorable phi/epsilon glycosidic bond angle combination. In contrast, octasaccharides from the other serotypes bind as solution-like conformers. Two water molecules are conserved in all P22 TSP complexes with octasaccharides of different serotypes. They line the dideoxyhexose binding pocket and force the S. Paratyphi A octasaccharides to bind as nonsolution conformers. This emphasizes the role of solvent as part of carbohydrate binding sites. KW - bacterial O-antigen KW - carbohydrate interaction KW - paratose KW - structural thermodynamics KW - tailspike protein Y1 - 2013 U6 - https://doi.org/10.1093/glycob/cws224 SN - 0959-6658 VL - 23 IS - 4 SP - 486 EP - 494 PB - Oxford Univ. Press CY - Cary ER - TY - JOUR A1 - Romero-Viana, Lidia A1 - Kienel, Ulrike A1 - Wilkes, Heinz A1 - Sachse, Dirk T1 - Growth-dependent hydrogen isotopic fractionation of algal lipid biomarkers in hypersaline Isabel Lake (Mexico) JF - Geochimica et cosmochimica acta : journal of the Geochemical Society and the Meteoritical Society N2 - In this study, we evaluated the potential of the hydrogen isotopic composition of algal lipid biomarkers as a proxy for past hydroclimatic variability in hypersaline Isabel Lake, Mexico (Eastern Pacific). We compared rainfall variability recorded in the region over the last 65 years with changes in delta D values of the most abundant compounds preserved in the uppermost 16 cm of lake sediment. Changes in delta D values of the 1,15-C-32 diol (delta D-diol), a specific biomarker of algal populations, were related to rainfall variability; specifically, n-alkyl diols were more deuterium-enriched (depleted) during wetter (drier) periods. Strikingly, neither the magnitude of lipid biomarker isotopic changes over interannual timescales (of up to 70-80 parts per thousand) nor the direction of that variability can be explained by changes in delta D values of the water source or salinity fluctuations (approximately 30 on the practical salinity scale) controlled by seasonal rainfall. However, changes in sedimentary biomarker composition, higher total organic carbon content and less negative delta C-13 values of the 1,15-C-32 diol indicate enhanced algal growth during wetter periods. We find that these conditions result in less negative delta D values of n-alkyl diols. We hypothesize that due to higher lipid demand during enhanced algal growth, an increasing proportion of hydrogen for lipid synthesis is derived from the cytosol via oxidation of polysaccharides, which may cause a deuterium enrichment of the acetogenic compounds. This study has significant implications for paleohydrological reconstructions using algal lipid delta D values, particularly in highly seasonal environments such as Isabel Lake. In such environments, delta D values of specific algal lipid biomarkers may not record the full seasonal cycle in source water delta D but appear to be mainly controlled by the physiological state of algal populations. Our data provide the first evidence that changes in D/H fractionation due to algal growth conditions can be recorded in sediments. For paleoclimate reconstructions in such environments, algal growth conditions should be constrained with additional proxy data (delta C-13 values of the same biomarkers), as the net D/H fractionation between water and lipids may not have been constant over time. Y1 - 2013 U6 - https://doi.org/10.1016/j.gca.2012.12.017 SN - 0016-7037 VL - 106 IS - 4 SP - 490 EP - 500 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Nguyen, Hung M. A1 - Schippers, Jos H. M. A1 - Goni-Ramos, Oscar A1 - Christoph, Mathias P. A1 - Dortay, Hakan A1 - van der Hoorn, Renier A. L. A1 - Müller-Röber, Bernd T1 - An upstream regulator of the 26S proteasome modulates organ size in Arabidopsis thaliana JF - The plant journal N2 - In both animal and plant kingdoms, body size is a fundamental but still poorly understood attribute of biological systems. Here we report that the Arabidopsis NAC transcription factor Regulator of Proteasomal Gene Expression' (RPX) controls leaf size by positively modulating proteasome activity. We further show that the cis-element recognized by RPX is evolutionarily conserved between higher plant species. Upon over-expression of RPX, plants exhibit reduced growth, which may be reversed by a low concentration of the pharmacological proteasome inhibitor MG132. These data suggest that the rate of protein turnover during growth is a critical parameter for determining final organ size. KW - Arabidopsis thaliana KW - organ size KW - evolution KW - leaf development KW - proteasome KW - gene regulatory network Y1 - 2013 U6 - https://doi.org/10.1111/tpj.12097 SN - 0960-7412 VL - 74 IS - 1 SP - 25 EP - 36 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Baumann, Otto A1 - Bauer, Alexandra T1 - Development of apical membrane organization and V-ATPase regulation in blowfly salivary glands JF - The journal of experimental biology N2 - Secretory cells in blowfly salivary gland are specialized via morphological and physiological attributes in order to serve their main function, i.e. the transport of solutes at a high rate in response to a hormonal stimulus, namely serotonin (5-HT). This study examines the way that 5-HT-insensitive precursor cells differentiate into morphologically complex 5-HT-responsive secretory cells. By means of immunofluorescence microscopy, immunoblotting and measurements of the transepithelial potential changes, we show the following. (1) The apical membrane of the secretory cells becomes organized into an elaborate system of canaliculi and is folded into pleats during the last pupal day and the first day of adulthood. (2) The structural reorganization of the apical membrane is accompanied by an enrichment of actin filaments and phosphorylated ERM protein (phospho-moesin) at this membrane domain and by the deployment of the membrane-integral part of vacuolar-type H+-ATPase (V-ATPase). These findings suggest a role for phospho-moesin, a linker between actin filaments and membrane components, in apical membrane morphogenesis. (3) The assembly and activation of V-ATPase can be induced immediately after eclosion by way of 8-CPT-cAMP, a membrane-permeant cAMP analogue. (4) 5-HT, however, produces the assembly and activation of V-ATPase only in flies aged for at least 2 h after eclosion, indicating that, at eclosion, the 5-HT receptor/adenylyl cyclase/cAMP signalling pathway is inoperative upstream of cAMP. (5) 5-HT activates both the Ca2+ signalling pathway and the cAMP signalling cascade in fully differentiated secretory cells. However, the functionality of these signalling cascades does not seem to be established in a tightly coordinated manner during cell differentation. KW - secretory cell KW - moesin KW - morphogenesis KW - serotonin KW - vacuolar ATPase KW - cAMP Y1 - 2013 U6 - https://doi.org/10.1242/jeb.077420 SN - 0022-0949 VL - 216 IS - 7 SP - 1225 EP - 1234 PB - Company of Biologists Limited CY - Cambridge ER - TY - JOUR A1 - Martin, Benjamin T. A1 - Jager, Tjalling A1 - Nisbet, Roger M. A1 - Preuss, Thomas G. A1 - Hammers-Wirtz, Monika A1 - Grimm, Volker T1 - Extrapolating ecotoxicological effects from individuals to populations - a generic approach based on Dynamic Energy Budget theory and individual-based modeling JF - Ecotoxicology N2 - Individual-based models (IBMs) predict how dynamics at higher levels of biological organization emerge from individual-level processes. This makes them a particularly useful tool for ecotoxicology, where the effects of toxicants are measured at the individual level but protection goals are often aimed at the population level or higher. However, one drawback of IBMs is that they require significant effort and data to design for each species. A solution would be to develop IBMs for chemical risk assessment that are based on generic individual-level models and theory. Here we show how one generic theory, Dynamic Energy Budget (DEB) theory, can be used to extrapolate the effect of toxicants measured at the individual level to effects on population dynamics. DEB is based on first principles in bioenergetics and uses a common model structure to model all species. Parameterization for a certain species is done at the individual level and allows to predict population-level effects of toxicants for a wide range of environmental conditions and toxicant concentrations. We present the general approach, which in principle can be used for all animal species, and give an example using Daphnia magna exposed to 3,4-dichloroaniline. We conclude that our generic approach holds great potential for standardized ecological risk assessment based on ecological models. Currently, available data from standard tests can directly be used for parameterization under certain circumstances, but with limited extra effort standard tests at the individual would deliver data that could considerably improve the applicability and precision of extrapolation to the population level. Specifically, the measurement of a toxicant's effect on growth in addition to reproduction, and presenting data over time as opposed to reporting a single EC50 or dose response curve at one time point. KW - Population KW - Dynamic Energy Budget KW - Individual-based model KW - Sub-lethal effects KW - Physiological mode of action KW - Effect model Y1 - 2013 U6 - https://doi.org/10.1007/s10646-013-1049-x SN - 0963-9292 VL - 22 IS - 3 SP - 574 EP - 583 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Tikhonenko, Irina A1 - Magidson, Valentin A1 - Gräf, Ralph A1 - Khodjakov, Alexey A1 - Koonce, Michael P. T1 - A kinesin-mediated mechanism that couples centrosomes to nuclei JF - Cellular and molecular life sciences N2 - The M-type kinesin isoform, Kif9, has recently been implicated in maintaining a physical connection between the centrosome and nucleus in Dictyostelium discoideum. However, the mechanism by which Kif9 functions to link these two organelles remains obscure. Here we demonstrate that the Kif9 protein is localized to the nuclear envelope and is concentrated in the region underlying the centrosome point of attachment. Nuclear anchorage appears mediated through a specialized transmembrane domain located in the carboxyl terminus. Kif9 interacts with microtubules in in vitro binding assays and effects an endwise depolymerization of the polymer. These results suggest a model whereby Kif9 is anchored to the nucleus and generates a pulling force that reels the centrosome up against the nucleus. This is a novel activity for a kinesin motor, one important for progression of cells into mitosis and to ensure centrosome-nuclear parity in a multinuclear environment. KW - Centrosome KW - Kinesin KW - Microtubule KW - Dictyostelium Y1 - 2013 U6 - https://doi.org/10.1007/s00018-012-1205-0 SN - 1420-682X VL - 70 IS - 7 SP - 1285 EP - 1296 PB - Springer CY - Basel ER - TY - JOUR A1 - Andree, Kai T1 - A note on merger in mixed duopoly - Bertrand versus Cournot JF - Journal of economics N2 - In this note we analyze the incentives to merge in a mixed duopoly if firms compete in prices or quantities. Our model framework mainly follows Barcena-Ruiz and Garzon (J Econ 80:27-42, 2003) who set up the model with quantity competition. We extend their analysis by analyzing the case of competition in prices. Further we compare the incentives to merge with Bertrand and Cournot competition. Comparing quantity with price competition we can show that a merger is more likely with Cournot competition than with Bertrand competition. KW - Merger KW - Price competition KW - Mixed duopoly Y1 - 2013 U6 - https://doi.org/10.1007/s00712-012-0280-x SN - 0931-8658 VL - 108 IS - 3 SP - 291 EP - 298 PB - Springer CY - Wien ER - TY - JOUR A1 - Rauf, Mamoona A1 - Arif, Muhammad A1 - Dortay, Hakan A1 - Matallana-Ramirez, Lilian P. A1 - Waters, Mark T. A1 - Nam, Hong Gil A1 - Lim, Pyung-Ok A1 - Müller-Röber, Bernd A1 - Balazadeh, Salma T1 - ORE1 balances leaf senescence against maintenance by antagonizing G2-like-mediated transcription JF - EMBO reports N2 - Leaf senescence is a key physiological process in all plants. Its onset is tightly controlled by transcription factors, of which NAC factor ORE1 (ANAC092) is crucial in Arabidopsis thaliana. Enhanced expression of ORE1 triggers early senescence by controlling a downstream gene network that includes various senescence-associated genes. Here, we report that unexpectedly ORE1 interacts with the G2-like transcription factors GLK1 and GLK2, which are important for chloroplast development and maintenance, and thereby for leaf maintenance. ORE1 antagonizes GLK transcriptional activity, shifting the balance from chloroplast maintenance towards deterioration. Our finding identifies a new mechanism important for the control of senescence by ORE1. KW - transcription factor KW - senescence KW - chloroplast KW - protein-protein interaction Y1 - 2013 U6 - https://doi.org/10.1038/embor.2013.24 SN - 1469-221X VL - 14 IS - 4 SP - 382 EP - 388 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Sarmento, Juliano Sarmento A1 - Jeltsch, Florian A1 - Thuiller, Wilfried A1 - Higgins, Steven A1 - Midgley, Guy F. A1 - Rebelo, Anthony G. A1 - Rouget, Mathieu A1 - Schurr, Frank Martin T1 - Impacts of past habitat loss and future climate change on the range dynamics of South African Proteaceae JF - Diversity & distributions : a journal of biological invasions and biodiversity N2 - Aim To assess how habitat loss and climate change interact in affecting the range dynamics of species and to quantify how predicted range dynamics depend on demographic properties of species and the severity of environmental change. Location South African Cape Floristic Region. Methods We use data-driven demographic models to assess the impacts of past habitat loss and future climate change on range size, range filing and abundances of eight species of woody plants (Proteaceae). The species-specific models employ a hybrid approach that simulates population dynamics and long-distance dispersal on top of expected spatio-temporal dynamics of suitable habitat. Results Climate change was mainly predicted to reduce range size and range filling (because of a combination of strong habitat shifts with low migration ability). In contrast, habitat loss mostly decreased mean local abundance. For most species and response measures, the combination of habitat loss and climate change had the most severe effect. Yet, this combined effect was mostly smaller than expected from adding or multiplying effects of the individual environmental drivers. This seems to be because climate change shifts suitable habitats to regions less affected by habitat loss. Interspecific variation in range size responses depended mostly on the severity of environmental change, whereas responses in range filling and local abundance depended mostly on demographic properties of species. While most surviving populations concentrated in areas that remain climatically suitable, refugia for multiple species were overestimated by simply overlying habitat models and ignoring demography. Main conclusions Demographic models of range dynamics can simultaneously predict the response of range size, abundance and range filling to multiple drivers of environmental change. Demographic knowledge is particularly needed to predict abundance responses and to identify areas that can serve as biodiversity refugia under climate change. These findings highlight the need for data-driven, demographic assessments in conservation biogeography. KW - biodiversity refugia KW - CFR Proteaceae KW - climate change KW - demographic properties KW - habitat loss KW - local abundances KW - process-based range models KW - range filling KW - range size KW - species distribution models Y1 - 2013 U6 - https://doi.org/10.1111/ddi.12011 SN - 1366-9516 VL - 19 IS - 4 SP - 363 EP - 376 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Zöller, Gert A1 - Holschneider, Matthias A1 - Hainzl, Sebastian T1 - The Maximum Earthquake Magnitude in a Time Horizon: Theory and Case Studies JF - Bulletin of the Seismological Society of America N2 - We show how the maximum magnitude within a predefined future time horizon may be estimated from an earthquake catalog within the context of Gutenberg-Richter statistics. The aim is to carry out a rigorous uncertainty assessment, and calculate precise confidence intervals based on an imposed level of confidence a. In detail, we present a model for the estimation of the maximum magnitude to occur in a time interval T-f in the future, given a complete earthquake catalog for a time period T in the past and, if available, paleoseismic events. For this goal, we solely assume that earthquakes follow a stationary Poisson process in time with unknown productivity Lambda and obey the Gutenberg-Richter law in magnitude domain with unknown b-value. The random variables. and b are estimated by means of Bayes theorem with noninformative prior distributions. Results based on synthetic catalogs and on retrospective calculations of historic catalogs from the highly active area of Japan and the low-seismicity, but high-risk region lower Rhine embayment (LRE) in Germany indicate that the estimated magnitudes are close to the true values. Finally, we discuss whether the techniques can be extended to meet the safety requirements for critical facilities such as nuclear power plants. For this aim, the maximum magnitude for all times has to be considered. In agreement with earlier work, we find that this parameter is not a useful quantity from the viewpoint of statistical inference. Y1 - 2013 U6 - https://doi.org/10.1785/0120120013 SN - 0037-1106 VL - 103 IS - 2A SP - 860 EP - 875 PB - Seismological Society of America CY - Albany ER - TY - JOUR A1 - Hancock, Christine A1 - Wäschke, Nicole A1 - Schumacher, Uta A1 - Linsenmair, Karl Eduard A1 - Meiners, Torsten A1 - Obermaier, Elisabeth T1 - Fertilizer application decreases insect abundance on Plantago lanceolata - a large-scale experiment in three geographic regions JF - Arthropod-plant interactions : an international journal devoted to studies on interactions of insects, mites, and other arthropods with plants N2 - Humans have substantially altered the nitrogen cycle of ecosystems through the application of agricultural fertilizer. Fertilization may not only affect plant species diversity, but also insect dynamics by altering plant nitrogen supplies. We investigated the effect of experimental fertilization on the vegetation, with the ribwort plantain as the focal plant, and on higher trophic levels on differently managed grasslands throughout Germany. Over a period of 2 years, we examined two specialist herbivores and their parasitoid on Plantago lanceolata L., and the composition and structure of the surrounding vegetation. Over 70 sites in three geographic regions, within the large-scale project "German Biodiversity Exploratories", were included in the study. The model system consisted of the host plant P. lanceolata L., the monophagous weevils Mecinus labilis Herbst and M. pascuorum Gyllenhal, and their parasitoid Mesopolobus incultus Walker. Fertilization decreased plant species richness and host plant abundance, whereas it enhanced the total vegetation growth. The increased size and heigher leaf nitrogen content did not improve herbivore performance. On the contrary, the abundance of the two herbivores was decreased by fertilization. The parasitoid depended on the abundance of one of its hosts, M. pascuorum (positively density-dependent). Reduced herbivore abundance due to fertilization might be explained by a lower abundance of the host plant, a lower stalk number, and by changed patterns of host localization within higher vegetation. Fertilization negatively affected the third trophic level by cascading up via host abundance. The relationships between fertilization, surrounding vegetation and the tritrophic system were measured throughout the three regions and over the 2-year period. Our findings present consequences of intensification for a plant-herbivore-parasitoid system, and may have significant implications for the conservation of multitrophic systems in managed grasslands. KW - Fertilization KW - Nitrogen KW - Tritrophic interaction KW - Plant species richness KW - Grassland management KW - Vegetation structure Y1 - 2013 U6 - https://doi.org/10.1007/s11829-012-9237-9 SN - 1872-8855 SN - 1872-8847 VL - 7 IS - 2 SP - 147 EP - 158 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Martin, Benjamin T. A1 - Jager, Tjalling A1 - Nisbet, Roger M. A1 - Preuss, Thomas G. A1 - Grimm, Volker T1 - Predicting population dynamics from the properties of individuals - a cross-level test of dynamic energy budget theory JF - The American naturalist : a bi-monthly journal devoted to the advancement and correlation of the biological sciences N2 - Individual-based models (IBMs) are increasingly used to link the dynamics of individuals to higher levels of biological organization. Still, many IBMs are data hungry, species specific, and time-consuming to develop and analyze. Many of these issues would be resolved by using general theories of individual dynamics as the basis for IBMs. While such theories have frequently been examined at the individual level, few cross-level tests exist that also try to predict population dynamics. Here we performed a cross-level test of dynamic energy budget (DEB) theory by parameterizing an individual-based model using individual-level data of the water flea, Daphnia magna, and comparing the emerging population dynamics to independent data from population experiments. We found that DEB theory successfully predicted population growth rates and peak densities but failed to capture the decline phase. Further assumptions on food-dependent mortality of juveniles were needed to capture the population dynamics after the initial population peak. The resulting model then predicted, without further calibration, characteristic switches between small-and large-amplitude cycles, which have been observed for Daphnia. We conclude that cross-level tests help detect gaps in current individual-level theories and ultimately will lead to theory development and the establishment of a generic basis for individual-based models and ecology. KW - population dynamics KW - dynamic energy budget theory KW - bioenergetics KW - individual-based model Y1 - 2013 U6 - https://doi.org/10.1086/669904 SN - 0003-0147 VL - 181 IS - 4 SP - 506 EP - 519 PB - Univ. of Chicago Press CY - Chicago ER - TY - JOUR A1 - Eschenlohr, Andrea A1 - Battiato, Marco A1 - Maldonado, R. A1 - Pontius, N. A1 - Kachel, T. A1 - Holldack, K. A1 - Mitzner, Rolf A1 - Föhlisch, Alexander A1 - Oppeneer, P. M. A1 - Stamm, C. T1 - Ultrafast spin transport as key to femtosecond demagnetization JF - Nature materials N2 - Irradiating a ferromagnet with a femtosecond laser pulse is known to induce an ultrafast demagnetization within a few hundred femtoseconds. Here we demonstrate that direct laser irradiation is in fact not essential for ultrafast demagnetization, and that electron cascades caused by hot electron currents accomplish it very efficiently. We optically excite a Au/Ni layered structure in which the 30 nm Au capping layer absorbs the incident laser pump pulse and subsequently use the X-ray magnetic circular dichroism technique to probe the femtosecond demagnetization of the adjacent 15 nm Ni layer. A demagnetization effect corresponding to the scenario in which the laser directly excites the Ni film is observed, but with a slight temporal delay. We explain this unexpected observation by means of the demagnetizing effect of a superdiffusive current of non-equilibrium, non-spin-polarized electrons generated in the Au layer. Y1 - 2013 U6 - https://doi.org/10.1038/NMAT3546 SN - 1476-1122 VL - 12 IS - 4 SP - 332 EP - 336 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Lange, Bastian A1 - Bürkner, Hans-Joachim T1 - Value creation in scene-based music production - the case of electronic club music in Germany JF - Economic geography N2 - The focus of this article is on the variability of value creation in the popular music industry. Recent trends in electronic music have been based on both the valorization of global tastes and of local specialities in performance and production. Depending on musical styles and market niches, local scenes have become important forces behind heterogeneous globalocal markets. At the same time, technological change and the virtualization of music production and distribution contribute to increasingly differentiated configurations of value creation. It is therefore necessary to reconstruct theoretically and empirically the new interplay among the local music production, digital media markets, and virtual communities that are involved. On the basis of empirical explorations in a German hot spot of electronic club-music production (the city of Berlin), the article indentifies local interaction practice and constellations of stakeholders. The findings show that value creation in these rapidly changing production scenes has moved away from the large-scale distribution of producer-induced media to audience-induced live performance and interactive soundtrack production. This change involves the rising importance of cultural embeddings such as taste building, reputation building among artists and producers, and local community building. Starting from an open theoretical problematization of value creation with regard to fluid scenes and shifting modes of production, the results of first empirical reconstructions are taken as inputs to an evolving discussion on the configurations of value creation in consumer-based strands of music production. KW - music industry KW - value creation KW - value chain KW - creative economy KW - Berlin Y1 - 2013 U6 - https://doi.org/10.1111/ecge.12002 SN - 0013-0095 VL - 89 IS - 2 SP - 149 EP - 169 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Fischer, Martin H. A1 - Riello, Marianna A1 - Giordano, Bruno L. A1 - Rusconi, Elena T1 - Singing numbers ... in cognitive space - a dual-task study of the link between pitch, space, and numbers JF - Topics in cognitive science N2 - We assessed the automaticity of spatial-numerical and spatial-musical associations by testing their intentionality and load sensitivity in a dual-task paradigm. In separate sessions, 16 healthy adults performed magnitude and pitch comparisons on sung numbers with variable pitch. Stimuli and response alternatives were identical, but the relevant stimulus attribute (pitch or number) differed between tasks. Concomitant tasks required retention of either color or location information. Results show that spatial associations of both magnitude and pitch are load sensitive and that the spatial association for pitch is more powerful than that for magnitude. These findings argue against the automaticity of spatial mappings in either stimulus dimension. KW - Auditory pitch KW - Dual task KW - Mental number line KW - SMARC KW - SNARC KW - Spatial coding Y1 - 2013 U6 - https://doi.org/10.1111/tops.12017 SN - 1756-8757 VL - 5 IS - 2 SP - 354 EP - 366 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Zhou, Wei A1 - Kliegl, Reinhold A1 - Yan, Ming T1 - A validation of parafoveal semantic information extraction in reading Chinese JF - Journal of research in reading : a journal of the United Kingdom Reading Association N2 - Parafoveal semantic processing has recently been well documented in reading Chinese sentences, presumably because of language-specific features. However, because of a large variation of fixation landing positions on pretarget words, some preview words actually were located in foveal vision when readers' eyes landed close to the end of the pretarget words. None of the previous studies has completely ruled out a possibility that the semantic preview effects might mainly arise from these foveally processed preview words. This case, whether previously observed positive evidence for parafoveal semantic processing can still hold, has been called into question. Using linear mixed models, we demonstrate in this study that semantic preview benefit from word N+1 decreased if fixation on pretarget word N was close to the preview. We argue that parafoveal semantic processing is not a consequence of foveally processed preview words. KW - semantic KW - preview benefit KW - reading KW - Chinese Y1 - 2013 U6 - https://doi.org/10.1111/j.1467-9817.2013.01556.x SN - 0141-0423 VL - 36 IS - 2 SP - S51 EP - S63 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Wang, Jing A1 - Fritzsch, Claire A1 - Bernarding, Johannes A1 - Holtze, Susanne A1 - Mauritz, Karl-Heinz A1 - Brunetti, Maddalena A1 - Dohle, Christian T1 - A comparison of neural mechanisms in mirror therapy and movement observation therapy JF - Journal of rehabilitation medicine : official journal of the UEMS European Board of Physical and Rehabilitation Medicine N2 - Objective: To compare lateralized cerebral activations elicited during self-initiated movement mirroring and observation of movements. Subjects: A total of 15 right-handed healthy subjects, age range 22-56 years. Methods: Functional imaging study comparing movement mirroring with movement observation, in both hands, in an otherwise identical setting. Imaging data were analysed using statistical parametric mapping software, with significance threshold set at p<0.01 (false discovery rate) and a minimum cluster size of 20 voxels. Results: Movement mirroring induced additional activation in primary and higher-order visual areas strictly contralateral to the limb seen by the subject. There was no significant difference of brain activity when comparing movement observation of somebody else's right hand with left hand. Conclusion: Lateralized cerebral activations are elicited by inversion of visual feedback (movement mirroring), but not by movement observation. KW - fMRI KW - mirror KW - movement KW - observation KW - precuneus Y1 - 2013 U6 - https://doi.org/10.2340/16501977-1127 SN - 1650-1977 VL - 45 IS - 4 SP - 410 EP - 413 PB - Foundation for Rehabilitation Information CY - Uppsala ER - TY - JOUR A1 - Feigenbaum, Anna A1 - McCurdy, Patrick A1 - Frenzel, Fabian T1 - Towards a method for studying affect in (micro)politics - the Campfire Chats Project and the Occupy movement JF - Parallax Y1 - 2013 U6 - https://doi.org/10.1080/13534645.2013.778493 SN - 1353-4645 VL - 19 IS - 2 SP - 21 EP - 37 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Hamann, Göran A1 - Tronicke, Jens A1 - Steelman, Colby M. A1 - Endres, Anthony L. T1 - Spectral velocity analysis for the determination of ground-wave velocities and their uncertainties in multi-offset GPR data JF - Near surface geophysics N2 - In many hydrological applications, ground-wave velocity measurements are increasingly used to map and monitor shallow soil water content. In this study, we propose an automated spectral velocity analysis method to determine the direct ground-wave (DGW) velocity from common midpoint (CMP) or multi-offset ground-penetrating radar (GPR) data. The method introduced in this paper is a variation of the well-known spectral velocity analysis for seismic and GPR reflection events where velocity spectra are computed using different coherency measures along hyperbolas following the normal moveout model. Here, the unnormalized cross-correlation is computed between waveforms across data gathers that are corrected with a linear moveout equation using a predefined range of velocities. Peaks in the resulting velocity spectra identify linear events in the GPR data gathers like DGW events and allow for estimating the corresponding velocities. In addition to obtaining a DGW velocity measurement, we propose a robust method to estimate the associated velocity uncertainties based on the width of the peak in the calculated velocity spectrum. Our proposed method is tested on synthetic data examples to evaluate the influence of subsurface velocity, surveying geometry and signal frequency on the accuracy of estimated ground-wave velocities. In addition, we investigate the influence of such velocity uncertainties on subsequent soil water content estimates using an established petrophysical relationship. Furthermore, we apply our approach to analyse field data, which were collected across a test site in Canada to monitor a wide range of seasonal soil moisture variations. A comparison between our spectral velocity estimates and results derived from manually picked ground-wave arrivals shows good agreement, which illustrates that our spectral velocity analysis is a feasible tool to analyse DGW arrivals in multi-offset GPR data gathers in an objective and more automated manner. Y1 - 2013 U6 - https://doi.org/10.3997/1873-0604.2012038 SN - 1569-4445 VL - 11 IS - 2 SP - 167 EP - 176 PB - European Association of Geoscientists & Engineers CY - Houten ER - TY - JOUR A1 - Beck, Jan A1 - Holloway, Jeremy D. A1 - Schwanghart, Wolfgang T1 - Undersampling and the measurement of beta diversity JF - Methods in ecology and evolution : an official journal of the British Ecological Society N2 - Beta diversity is a conceptual link between diversity at local and regional scales. Various additional methodologies of quantifying this and related phenomena have been applied. Among them, measures of pairwise (dis)similarity of sites are particularly popular. Undersampling, i.e. not recording all taxa present at a site, is a common situation in ecological data. Bias in many metrics related to beta diversity must be expected, but only few studies have explicitly investigated the properties of various measures under undersampling conditions. On the basis of an empirical data set, representing near-complete local inventories of the Lepidoptera from an isolated Pacific island, as well as simulated communities with varying properties, we mimicked different levels of undersampling. We used 14 different approaches to quantify beta diversity, among them dataset-wide multiplicative partitioning (i.e. true beta diversity') and pairwise site x site dissimilarities. We compared their values from incomplete samples to true results from the full data. We used these comparisons to quantify undersampling bias and we calculated correlations of the dissimilarity measures of undersampled data with complete data of sites. Almost all tested metrics showed bias and low correlations under moderate to severe undersampling conditions (as well as deteriorating precision, i.e. large chance effects on results). Measures that used only species incidence were very sensitive to undersampling, while abundance-based metrics with high dependency on the distribution of the most common taxa were particularly robust. Simulated data showed sensitivity of results to the abundance distribution, confirming that data sets of high evenness and/or the application of metrics that are strongly affected by rare species are particularly sensitive to undersampling. The class of beta measure to be used should depend on the research question being asked as different metrics can lead to quite different conclusions even without undersampling effects. For each class of metric, there is a trade-off between robustness to undersampling and sensitivity to rare species. In consequence, using incidence-based metrics carries a particular risk of false conclusions when undersampled data are involved. Developing bias corrections for such metrics would be desirable. KW - Bray-Curtis KW - Chao KW - Effective number of species KW - Incomplete inventories KW - Jaccard KW - Macrolepidoptera KW - Morisita KW - Morisita-Horn KW - NESS KW - Norfolk Island Y1 - 2013 U6 - https://doi.org/10.1111/2041-210x.12023 SN - 2041-210X VL - 4 IS - 4 SP - 370 EP - 382 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Dieckmann, M. E. A1 - Ahmed, H. A1 - Sarri, G. A1 - Doria, D. A1 - Kourakis, I. A1 - Romagnani, L. A1 - Pohl, Martin A1 - Borghesi, M. T1 - Parametric study of non-relativistic electrostatic shocks and the structure of their transition layer JF - Physics of plasmas N2 - Nonrelativistic electrostatic unmagnetized shocks are frequently observed in laboratory plasmas and they are likely to exist in astrophysical plasmas. Their maximum speed, expressed in units of the ion acoustic speed far upstream of the shock, depends only on the electron-to-ion temperature ratio if binary collisions are absent. The formation and evolution of such shocks is examined here for a wide range of shock speeds with particle-in-cell simulations. The initial temperatures of the electrons and the 400 times heavier ions are equal. Shocks form on electron time scales at Mach numbers between 1.7 and 2.2. Shocks with Mach numbers up to 2.5 form after tens of inverse ion plasma frequencies. The density of the shock-reflected ion beam increases and the number of ions crossing the shock thus decreases with an increasing Mach number, causing a slower expansion of the downstream region in its rest frame. The interval occupied by this ion beam is on a positive potential relative to the far upstream. This potential pre-heats the electrons ahead of the shock even in the absence of beam instabilities and decouples the electron temperature in the foreshock ahead of the shock from the one in the far upstream plasma. The effective Mach number of the shock is reduced by this electron heating. This effect can potentially stabilize nonrelativistic electrostatic shocks moving as fast as supernova remnant shocks. Y1 - 2013 U6 - https://doi.org/10.1063/1.4801447 SN - 1070-664X VL - 20 IS - 4 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - König, Niklas A1 - Reschke, Antje A1 - Wolter, Martin A1 - Müller, Steffen A1 - Mayer, Frank A1 - Baur, Heiner T1 - Plantar pressure trigger for reliable nerve stimulus application during dynamic H-reflex measurements JF - Gait & posture N2 - In dynamic H-reflex measurements, the standardisation of the nerve stimulation to the gait cycle is crucial to avoid misinterpretation due to altered pre-synaptic inhibition. In this pilot study, a plantar pressure sole was used to trigger the stimulation of the tibialis nerve with respect to the gait cycle. Consequently, the intersession reliability of the soleus muscle H-reflex during treadmill walking was investigated. Seven young participants performed walking trials on a treadmill at 5 km/h. The stimulating electrode was placed on the tibial nerve in the popliteal fossa. An EMG was recorded from the soleus muscle. To synchronize the stimulus to the gait cycle, initial heel strike was detected with a plantar pressure sole. Maximum H-reflex amplitude and M-wave amplitude were obtained and the Hmax/Mmax ratio was calculated. Data reveals excellent reliability, ICC = 0.89. Test-retest variability was 13.0% (+/- 11.8). The Bland-Altman analysis showed a systematic error of 2.4%. The plantar pressure sole was capable of triggering the stimulation of the tibialis nerve in a reliable way and offers a simple technique for the evaluation of reflex activity during walking. KW - Monosynaptic reflexes KW - Reflex reproducibility KW - Treadmill walking Y1 - 2013 U6 - https://doi.org/10.1016/j.gaitpost.2012.09.021 SN - 0966-6362 VL - 37 IS - 4 SP - 637 EP - 639 PB - Elsevier CY - Clare ER - TY - JOUR A1 - Abramowski, Attila A1 - Acero, F. A1 - Akhperjanian, A. G. A1 - Anton, Gisela A1 - Balenderan, Shangkari A1 - Balzer, Arnim A1 - Barnacka, Anna A1 - Becherini, Yvonne A1 - Tjus, J. Becker A1 - Behera, B. A1 - Bernlöhr, K. A1 - Birsin, E. A1 - Biteau, Jonathan A1 - Bochow, A. A1 - Boisson, Catherine A1 - Bolmont, J. A1 - Bordas, Pol A1 - Brucker, J. A1 - Brun, Francois A1 - Brun, Pierre A1 - Bulik, Tomasz A1 - Carrigan, Svenja A1 - Casanova, Sabrina A1 - Cerruti, M. A1 - Chadwick, Paula M. A1 - Chaves, Ryan C. G. A1 - Cheesebrough, A. A1 - Colafrancesco, Sergio A1 - Cologna, Gabriele A1 - Conrad, Jan A1 - Couturier, C. A1 - Dalton, M. A1 - Daniel, M. K. A1 - Davids, I. D. A1 - Degrange, B. A1 - Deil, C. A1 - deWilt, P. A1 - Dickinson, H. J. A1 - Djannati-Ataï, A. A1 - Domainko, W. A1 - Drury, L. O&rsquo A1 - C., A1 - Dubus, G. A1 - Dutson, K. A1 - Dyks, J. A1 - Dyrda, M. A1 - Egberts, Kathrin A1 - Eger, P. A1 - Espigat, P. A1 - Fallon, L. A1 - Farnier, C. A1 - Fegan, S. A1 - Feinstein, F. A1 - Fernandes, M. V. A1 - Fernandez, D. A1 - Fiasson, A. A1 - Fontaine, G. A1 - Foerster, A. A1 - Fussling, Matthias A1 - Gajdus, M. A1 - Gallant, Y. A. A1 - Garrigoux, T. A1 - Gast, H. A1 - Giebels, B. A1 - Glicenstein, J. F. A1 - Glueck, B. A1 - Goering, D. A1 - Grondin, M. -H. A1 - Grudzinska, M. A1 - Haeffner, S. A1 - Hague, J. D. A1 - Hahn, J. A1 - Hampf, D. A1 - Harris, J. A1 - Heinz, S. A1 - Heinzelmann, G. A1 - Henri, G. A1 - Hermann, G. A1 - Hillert, A. A1 - Hinton, James Anthony A1 - Hofmann, W. A1 - Hofverberg, P. A1 - Holler, M. A1 - Horns, D. A1 - Jacholkowska, A. A1 - Jahn, C. A1 - Jamrozy, M. A1 - Jung, I. A1 - Kastendieck, M. A. A1 - Katarzynski, K. A1 - Katz, U. A1 - Kaufmann, S. A1 - Khelifi, B. A1 - Klepser, S. A1 - Klochkov, D. A1 - Kluzniak, W. A1 - Kneiske, T. A1 - Kolitzus, D. A1 - Komin, Nu A1 - Kosack, K. A1 - Kossakowski, R. A1 - Krayzel, F. A1 - Krueger, P. P. A1 - Laffon, H. A1 - Lamanna, G. A1 - Lefaucheur, J. A1 - Lemoine-Goumard, M. A1 - Lenain, J. -P. A1 - Lennarz, D. A1 - Lohse, T. A1 - Lopatin, A. A1 - Lu, C. -C. A1 - Marandon, V. A1 - Marcowith, Alexandre A1 - Masbou, J. A1 - Maurin, G. A1 - Maxted, N. A1 - Mayer, M. A1 - McComb, T. J. L. A1 - Medina, M. C. A1 - Mehault, J. A1 - Menzler, U. A1 - Moderski, R. A1 - Mohamed, M. A1 - Moulin, Emmanuel A1 - Naumann, C. L. A1 - Naumann-Godo, M. A1 - de Naurois, M. A1 - Nedbal, D. A1 - Nguyen, N. A1 - Niemiec, J. A1 - Nolan, S. J. A1 - Ohm, S. A1 - Wilhelmi, E. de Ona A1 - Opitz, B. A1 - Ostrowski, M. A1 - Oya, I. A1 - Panter, M. A1 - Parsons, R. D. A1 - Arribas, M. Paz A1 - Pekeur, N. W. A1 - Pelletier, G. A1 - Perez, J. A1 - Petrucci, P. -O. A1 - Peyaud, B. A1 - Pita, S. A1 - Puehlhofer, G. A1 - Punch, M. A1 - Quirrenbach, A. A1 - Raab, S. A1 - Raue, M. A1 - Reimer, A. A1 - Reimer, O. A1 - Renaud, M. A1 - de los Reyes, R. A1 - Rieger, F. A1 - Ripken, J. A1 - Rob, L. A1 - Rosier-Lees, S. A1 - Rowell, G. A1 - Rudak, B. A1 - Rulten, C. B. A1 - Sahakian, V. A1 - Sanchez, David M. A1 - Santangelo, Andrea A1 - Schlickeiser, R. A1 - Schulz, A. A1 - Schwanke, U. A1 - Schwarzburg, S. A1 - Schwemmer, S. A1 - Sheidaei, F. A1 - Skilton, J. L. A1 - Sol, H. A1 - Spengler, G. A1 - Stawarz, L. A1 - Steenkamp, R. A1 - Stegmann, Christian A1 - Stinzing, F. A1 - Stycz, K. A1 - Sushch, Iurii A1 - Szostek, A. A1 - Tavernet, J. -P. A1 - Terrier, R. A1 - Tluczykont, M. A1 - Trichard, C. A1 - Valerius, K. A1 - van Eldik, C. A1 - Vasileiadis, G. A1 - Venter, C. A1 - Viana, A. A1 - Vincent, P. A1 - Voelk, H. J. A1 - Volpe, F. A1 - Vorobiov, S. A1 - Vorster, M. A1 - Wagner, S. J. A1 - Ward, M. A1 - White, R. A1 - Wierzcholska, A. A1 - Wouters, D. A1 - Zacharias, M. A1 - Zajczyk, A. A1 - Zdziarski, A. A. A1 - Zech, Alraune A1 - Zechlin, H. -S. A1 - Pelat, D. T1 - Discovery of TeV gamma-ray emission from PKS 0447-439 and derivation of an upper limit on its redshift JF - ASTRONOMY & ASTROPHYSICS N2 - Very high-energy gamma-ray emission from PKS 0447-439 was detected with the H. E. S. S. Cherenkov telescope array in December 2009. This blazar is one of the brightest extragalactic objects in the Fermi bright source list and has a hard spectrum in the MeV to GeV range. In the TeV range, a photon index of 3.89 +/- 0.37 (stat) +/- 0.22 (sys) and a flux normalisation at 1 TeV, phi(1) (TeV) = (3.5 +/- 1.1(stat) +/- 0.9(sys)) x 10(-13) cm(-2) s(-1) TeV-1 were found. The detection with H. E. S. S. triggered observations in the X-ray band with the Swift and RXTE telescopes. Simultaneous UV and optical data from Swift UVOT and data from the optical telescopes ATOM and ROTSE are also available. The spectrum and light curve measured with H. E. S. S. are presented and compared to the multi-wavelength data at lower energies. A rapid flare is seen in the Swift XRT and RXTE data, together with a flux variation in the UV band, at a time scale of the order of one day. A firm upper limit of z < 0.59 on the redshift of PKS 0447-439 is derived from the combined Fermi-LAT and H. E. S. S. data, given the assumptions that there is no upturn in the intrinsic spectrum above the Fermi-LAT energy range and that absorption on the extragalactic background light (EBL) is not weaker than the lower limit provided by current models. The spectral energy distribution is well described by a simple one-zone synchrotron self-Compton scenario, if the redshift of the source is less than z less than or similar to 0.4. KW - galaxies: active KW - BL Lacertae objects: individual: PKS 0447-439 KW - radiation mechanisms: non-thermal KW - gamma rays: galaxies Y1 - 2013 U6 - https://doi.org/10.1051/0004-6361/201321108 SN - 0004-6361 VL - 552 IS - 4 PB - EDP SCIENCES S A CY - LES ULIS CEDEX A ER - TY - JOUR A1 - Jagdhuber, Thomas A1 - Hajnsek, Irena A1 - Bronstert, Axel A1 - Papathanassiou, Konstantinos Panagiotis T1 - Soil moisture estimation under low vegetation cover using a multi-angular polarimetric decomposition JF - IEEE transactions on geoscience and remote sensing N2 - The estimation of volumetric soil moisture under low agricultural vegetation from fully polarimetric synthetic aperture radar (SAR) data at L-band using a multi-angular polarimetric decomposition is investigated. Radar polarimetry provides the framework to decompose the backscattered signal into different canonical scattering mechanisms referring to scattering contributions from the underlying soil and the vegetation cover. Multiangular observation diversity further increases the information space for soil moisture inversion enabling higher inversion rates and a stable inversion performance. The developed approach was applied on the multi-angular L-band data set acquired by German Aerospace Center's ESAR sensor as part of the OPAQUE campaign in 2008. The obtained results are compared against ground measurements collected by the OPAQUE team over a variety of vegetated agricultural fields. The validation of the estimated against ground measured soil moisture results in an root mean square error level of 6-8 vol.% including all test fields with a variety of crop types. KW - Multi-angular model-based decomposition KW - polarimetric SAR KW - soil moisture Y1 - 2013 U6 - https://doi.org/10.1109/TGRS.2012.2209433 SN - 0196-2892 VL - 51 IS - 4 SP - 2201 EP - 2215 PB - Inst. of Electr. and Electronics Engineers CY - Piscataway ER - TY - JOUR A1 - Martin-Martin, J. D. A1 - Gomez-Rivas, E. A1 - Bover-Arnal, T. A1 - Trave, A. A1 - Salas, R. A1 - Moreno-Bedmar, J. A. A1 - Tomas, S. A1 - Corbella, M. A1 - Teixell, A. A1 - Verges, J. A1 - Stafford, S. L. T1 - The Upper Aptian to Lower Albian syn-rift carbonate succession of the southern Maestrat Basin (Spain): Facies architecture and fault-controlled stratabound dolostones JF - CRETACEOUS RESEARCH N2 - Syn-rift shallow-marine carbonates of Late Aptian to Early Albian age in the southern Maestrat Basin (E Spain) register the thickest Aptian sedimentary record of the basin, and one of the most complete carbonate successions of this age reported in the northern Tethyan margin. The host limestones (Benassal Formation) are partially replaced by dolostones providing a new case study of fault-controlled hydrothermal dolomitization. The syn-rift sediments filled a graben controlled by normal basement faults. The Benassal Fm was deposited in a carbonate ramp with scarce siliciclastic input. The lithofacies are mainly characterized by the presence of orbitolinid foraminifera, corals and rudist bivalves fauna. The succession is stacked in three transgressive-regressive sequences (T-R) bounded by surfaces with sequence stratigraphic significance. The third sequence, which is reported for the first time in the basin, is formed by fully marine lithofacies of Albian age and represents the marine equivalent to the continental deposits of the Escucha Fm in the rest of the basin. The dolomitization of the host rock is spatially associated with the basement faults, and thus is fault-controlled. The dolostone forms seismic-scale stratabound tabular geobodies that extend several kilometres away from the fault zones, mostly in the hanging wall blocks, and host Mississippi Valley Type (MVT) deposits. The dolostones preferentially replaced middle to inner ramp grain-dominated fades from the third T-R sequences consisting of bioclastic packestones and peloidal grainstones. Field and petrology data indicate that the replacement took place after early calcite cementation and compaction, most likely during the Late Cretaceous post-rift stage of the basin. The dolostone registers the typical hydrothermal paragenesis constituted by the host limestone replacement, dolomite cementation and sulfide MVT mineralization. The Aptian succession studied provides a stratigraphic framework that can be used for oil exploration in age-equivalent rocks, especially in the Valencia Trough, offshore Spain. Moreover, this new case study constitutes a world class outcrop analogue for similar partially stratabound, dolomitized limestone reservoirs worldwide. (c) 2013 Elsevier Ltd. All rights reserved. KW - Aptian KW - Carbonate platform KW - Fault-controlled KW - Dolomitization KW - Maestrat Basin Y1 - 2013 U6 - https://doi.org/10.1016/j.cretres.2012.12.008 SN - 0195-6671 SN - 1095-998X VL - 41 IS - 4 SP - 217 EP - 236 PB - ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD CY - LONDON ER - TY - JOUR A1 - Heydari, Esmaeil A1 - Flehr, Roman A1 - Stumpe, Joachim T1 - Influence of spacer layer on enhancement of nanoplasmon-assisted random lasing JF - Applied physics letters N2 - Threshold reduction and emission enhancement are reported for a gold nanoparticle-based waveguided random laser, exploiting the localized surface plasmon resonance excitation. It was experimentally found that a proper thickness of the spacer layer between the gold nanoparticles and the gain layer enhances the random laser performance. It tunes the coupling between the gain polymer and the gold nanoparticles and avoids the quenching of emission in close contact to the gold nanoparticles which is considered as one of the main sources of loss in the current laser system. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4800776] Y1 - 2013 U6 - https://doi.org/10.1063/1.4800776 SN - 0003-6951 VL - 102 IS - 13 PB - American Institute of Physics CY - Melville ER - TY - JOUR A1 - Schiefele, Ulrich T1 - Response to engeser (2012) on the nature of flow experience JF - Psychological reports N2 - Engeser (2012) argued that the experience of flow is multifaceted and can only be measured validly by taking into account all relevant components. Although the possibility that flow includes several components cannot be excluded, there is weak evidence for Engeser's proposition. In support of a unidimensional interpretation of flow, theoretical, methodological, and empirical arguments are presented. Y1 - 2013 U6 - https://doi.org/10.2466/04.PR0.112.2.529-532 SN - 0033-2941 VL - 112 IS - 2 SP - 529 EP - 532 PB - Sage Publ. CY - Missoula ER - TY - JOUR A1 - Todt, Helge Tobias A1 - Kniazev, A. Y. A1 - Gvaramadze, V. V. A1 - Hamann, Wolf-Rainer A1 - Buckley, D. A1 - Crause, L. A1 - Crawford, S. M. A1 - Gulbis, A. A. S. A1 - Hettlage, C. A1 - Hooper, E. A1 - Husser, T. -O. A1 - Kotze, P. A1 - Loaring, N. A1 - Nordsieck, K. H. A1 - O'Donoghue, D. A1 - Pickering, T. A1 - Potter, S. A1 - Romero-Colmenero, E. A1 - Vaisanen, P. A1 - Williams, T. A1 - Wolf, M. T1 - Abell 48-a rare WN-type central star of a planetary nebula JF - Monthly notices of the Royal Astronomical Society N2 - A considerable fraction of the central stars of planetary nebulae (CSPNe) are hydrogen-deficient. Almost all of these H-deficient central stars (CSs) display spectra with strong carbon and helium lines. Most of them exhibit emission-line spectra resembling those of massive WC stars. Therefore these stars are classed as CSPNe of spectral type [WC]. Recently, quantitative spectral analysis of two emission-line CSs, PB 8 and IC 4663, revealed that these stars do not belong to the [WC] class. Instead PB 8 has been classified as [WN/WC] type and IC 4663 as [WN] type. In this work we report the spectroscopic identification of another rare [WN] star, the CS of Abell 48. We performed a spectral analysis of Abell 48 with the Potsdam Wolf-Rayet (PoWR) models for expanding atmospheres. We find that the expanding atmosphere of Abell 48 is mainly composed of helium (85 per cent by mass), hydrogen (10 per cent) and nitrogen (5 per cent). The residual hydrogen and the enhanced nitrogen abundance make this object different from the other [WN] star IC 4663. We discuss the possible origin of this atmospheric composition. KW - stars: abundances KW - stars: AGB and post-AGB KW - stars: mass-loss KW - stars: Wolf-Rayet KW - planetary nebulae: general KW - planetary nebulae: individual: PN G029.0+00.4 Y1 - 2013 U6 - https://doi.org/10.1093/mnras/stt056 SN - 0035-8711 SN - 1365-2966 VL - 430 IS - 3 SP - 2302 EP - 2312 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Stright, Lisa A1 - Bernhardt, Anne A1 - Boucher, Alexandre T1 - DFTopoSim modeling topographically-controlled deposition of subseismic scale sandstone packages within a mass transport dominated deep-water channel belt JF - Mathematical geosciences : the official journal of the International Association for Mathematical Geosciences N2 - Facies bodies in geostatistical models of deep-water depositional environments generally represent channel-levee-overbank-lobe morphologies. Such models adequately capture one set of the erosional and depositional processes resulting from turbidity currents traveling downslope to the ocean basin floor. However, depositional morphologies diverge from the straight forward channel-levee-overbank-lobe paradigm when the topography of the slope or the shape of the basin impacts the timing and magnitude of turbidity current deposition. Subaqueous mass-transport-deposits (MTDs) present the need for an exception to the channel-levee-overbank-lobe archetype. Irregular surface topography of subaqueous MTDs can play a primary role in controlling sand deposition from turbidity currents. MTD topography creates mini-basins in which sand accumulates in irregularly-shaped deposits. These accumulations are difficult to laterally correlate using well-log data due to their variable and unpredictable shape and size. Prediction is further complicated because sandstone bodies typical of this setting are difficult to resolve in seismic-reflection data. An event-based model is presented, called DFTopoSim, which simulates debris flows and turbidity currents. The accommodation space on top of and between debris flow lobes is filled in by sand from turbidity currents. When applied to a subsurface case in the Molasse Basin of Upper Austria, DFTopoSim predicts sand packages consistent with observations from core, well, and seismic data and the interpretation of the sedimentologic processes. DFTopoSim expands the set of available geostatistical deep-water depositional models beyond the standard channel-levee-overbank-lobe model. KW - Geostatistics KW - Event-based modeling KW - Facies modeling KW - Deep-marine sedimentology KW - Submarine channel Y1 - 2013 U6 - https://doi.org/10.1007/s11004-013-9444-7 SN - 1874-8961 VL - 45 IS - 3 SP - 277 EP - 296 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Klenk, Tanja A1 - Pieper, Jonas T1 - Accountability in a privatized welfare state the case of the german hospital market JF - Administration & society N2 - One of the most striking features of recent public sector reform in Europe is privatization. This development raises questions of accountability: By whom and for what are managers of private for-profit organizations delivering public goods held accountable? Analyzing accountability mechanisms through the lens of an institutional organizational approach and on the empirical basis of hospital privatization in Germany, the article contributes to the empirical and theoretical understanding of public accountability of private actors. The analysis suggests that accountability is not declining but rather multiplying. The shifts in the locus and content of accountability cause organizational stress for private hospitals. KW - accountability KW - hospitals KW - privatization KW - welfare markets Y1 - 2013 U6 - https://doi.org/10.1177/0095399712451890 SN - 0095-3997 VL - 45 IS - 3 SP - 326 EP - 356 PB - Sage Publ. CY - Thousand Oaks ER -