@article{MeckelmannPfeiferRauh2013, author = {Meckelmann, Viola and Pfeifer, Caroline and Rauh, Hellgard}, title = {Family relationships in childhood, pubertal timing, and subsequent reproductive strategies among adolescents}, series = {South African journal of psychology}, volume = {43}, journal = {South African journal of psychology}, number = {1}, publisher = {Sage Publ.}, address = {London}, issn = {0081-2463}, doi = {10.1177/0081246312474408}, pages = {22 -- 33}, year = {2013}, abstract = {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.}, language = {en} } @article{WestendorfNegreteBaeetal.2013, author = {Westendorf, Christian and Negrete, Jose and Bae, Albert J. and Sandmann, Rabea and Bodenschatz, Eberhard and Beta, Carsten}, title = {Actin cytoskeleton of chemotactic amoebae operates close to the onset of oscillations}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {110}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {10}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1216629110}, pages = {3853 -- 3858}, year = {2013}, abstract = {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.}, language = {en} } @article{HarmaPihlasaloCywinskietal.2013, author = {Harma, Harri and Pihlasalo, Sari and Cywinski, Piotr J. and Mikkonen, Piia and Hammann, Tommy and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Hanninen, Pekka}, title = {Protein quantification using resonance energy transfer between donor nanoparticles and acceptor quantum dots}, series = {Analytical chemistry}, volume = {85}, journal = {Analytical chemistry}, number = {5}, publisher = {American Chemical Society}, address = {Washington}, issn = {0003-2700}, doi = {10.1021/ac303586n}, pages = {2921 -- 2926}, year = {2013}, abstract = {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.}, language = {en} } @article{JulichGrunerLoewenbergNeffeetal.2013, author = {Julich-Gruner, Konstanze K. and L{\"o}wenberg, Candy and Neffe, Axel T. and Behl, Marc and Lendlein, Andreas}, title = {Recent trends in the chemistry of shape-memory polymers}, series = {Macromolecular chemistry and physics}, volume = {214}, journal = {Macromolecular chemistry and physics}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1022-1352}, doi = {10.1002/macp.201200607}, pages = {527 -- 536}, year = {2013}, abstract = {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.}, language = {en} } @article{BeyeFoehlisch2013, author = {Beye, Martin and F{\"o}hlisch, Alexander}, title = {Soft X-ray probes of ultrafast dynamics for heterogeneous catalysis}, series = {Chemical physics : a journal devoted to experimental and theoretical research involving problems of both a chemical and physical nature}, volume = {414}, journal = {Chemical physics : a journal devoted to experimental and theoretical research involving problems of both a chemical and physical nature}, number = {5}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0301-0104}, doi = {10.1016/j.chemphys.2012.03.023}, pages = {130 -- 138}, year = {2013}, abstract = {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.}, language = {en} } @article{JechowNortonHaendeletal.2013, author = {Jechow, Andreas and Norton, B. G. and H{\"a}ndel, S. and Blums, V. and Streed, E. W. and Kielpinski, D.}, title = {Controllable optical phase shift over one radian from a single isolated atom}, series = {Physical review letters}, volume = {110}, journal = {Physical review letters}, number = {11}, publisher = {American Physical Society}, address = {College Park}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.110.113605}, pages = {5}, year = {2013}, abstract = {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}, language = {en} } @article{OsterlohBoeckmannNicolaeetal.2013, author = {Osterloh, Lukas and B{\"o}ckmann, Christine and Nicolae, Doina and Nemuc, Anca}, title = {Regularized inversion of microphysical atmospheric particle parameters - theory and application}, series = {Journal of computational physics}, volume = {237}, journal = {Journal of computational physics}, number = {11}, publisher = {Elsevier}, address = {San Diego}, issn = {0021-9991}, doi = {10.1016/j.jcp.2012.11.040}, pages = {79 -- 94}, year = {2013}, abstract = {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.}, language = {en} } @article{LemkePrietzelKoetz2013, author = {Lemke, Karina and Prietzel, Claudia Christina and Koetz, Joachim}, title = {Fluorescent gold clusters synthesized in a poly(ethyleneimine) modified reverse microemulsion}, series = {Journal of colloid and interface science}, volume = {394}, journal = {Journal of colloid and interface science}, publisher = {Elsevier}, address = {San Diego}, issn = {0021-9797}, doi = {10.1016/j.jcis.2012.11.057}, pages = {141 -- 146}, year = {2013}, abstract = {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.}, language = {en} } @article{Dell'AngelaAnniyevBeyeetal.2013, author = {Dell'Angela, M. and Anniyev, Toyli and Beye, Martin and Coffee, Ryan and F{\"o}hlisch, Alexander and Gladh, J. and Katayama, T. and Kaya, S. and Krupin, O. and LaRue, J. and Mogelhoj, A. and Nordlund, D. and Norskov, J. K. and Oberg, H. and Ogasawara, H. and Ostrom, H. and Pettersson, Lars G. M. and Schlotter, W. F. and Sellberg, J. A. and Sorgenfrei, Nomi and Turner, J. J. and Wolf, M. and Wurth, W. and Nilsson, A.}, title = {Real-time observation of surface bond breaking with an X-ray Laser}, series = {Science}, volume = {339}, journal = {Science}, number = {6125}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {0036-8075}, doi = {10.1126/science.1231711}, pages = {1302 -- 1305}, year = {2013}, abstract = {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.}, language = {en} } @article{KleinpeterWernerKoch2013, author = {Kleinpeter, Erich and Werner, Peter and Koch, Andreas}, title = {Push-pull allenes-conjugation, (anti)aromaticity and quantification of the push-pull character}, series = {Tetrahedron}, volume = {69}, journal = {Tetrahedron}, number = {11}, publisher = {Elsevier}, address = {Oxford}, issn = {0040-4020}, doi = {10.1016/j.tet.2013.01.027}, pages = {2436 -- 2445}, year = {2013}, abstract = {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.}, language = {en} } @article{PohlEichler2013, author = {Pohl, Martin and Eichler, David}, title = {Understanding TeV-band cosmic-ray anistropy}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {766}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, number = {1}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0004-637X}, doi = {10.1088/0004-637X/766/1/4}, pages = {9}, year = {2013}, abstract = {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.}, language = {en} } @article{TaftWiechertZhangetal.2013, author = {Taft, Linda and Wiechert, Uwe and Zhang, Hucai and Lei, Guoliang and Mischke, Steffen and Plessen, Birgit and Weynell, Marc and Winkler, Andreas and Riedel, Frank}, title = {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}, series = {Quaternary international : the journal of the International Union for Quaternary Research}, volume = {290}, journal = {Quaternary international : the journal of the International Union for Quaternary Research}, number = {1}, publisher = {Elsevier}, address = {Oxford}, issn = {1040-6182}, doi = {10.1016/j.quaint.2012.10.031}, pages = {282 -- 298}, year = {2013}, abstract = {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.}, language = {en} } @article{BlomeyerBuchmannLascorzetal.2013, author = {Blomeyer, Dorothea and Buchmann, Arlette F. and Lascorz, Jesus and Zimmermann, Ulrich S. and Esser, G{\"u}nter and Desrivieres, Sylvane and Schmidt, Martin H. and Banaschewski, Tobias and Schumann, Gunter and Laucht, Manfred}, title = {Association of PER2 genotype and stressful life events with alcohol drinking in young adults}, series = {PLoS one}, volume = {8}, journal = {PLoS one}, number = {3}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0059136}, pages = {7}, year = {2013}, abstract = {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.}, language = {en} } @article{KuptsovKuznetsovPikovskij2013, author = {Kuptsov, Pavel V. and Kuznetsov, Sergey P. and Pikovskij, Arkadij}, title = {Hyperbolic chaos at blinking coupling of noisy oscillators}, series = {Physical review : E, Statistical, nonlinear and soft matter physics}, volume = {87}, journal = {Physical review : E, Statistical, nonlinear and soft matter physics}, number = {3}, publisher = {American Physical Society}, address = {College Park}, issn = {1539-3755}, doi = {10.1103/PhysRevE.87.032912}, pages = {7}, year = {2013}, abstract = {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}, language = {en} } @article{KomarovPikovskij2013, author = {Komarov, Maxim and Pikovskij, Arkadij}, title = {Dynamics of multifrequency oscillator communities}, series = {Physical review letters}, volume = {110}, journal = {Physical review letters}, number = {13}, publisher = {American Physical Society}, address = {College Park}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.110.134101}, pages = {5}, year = {2013}, abstract = {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}, language = {en} } @article{PingelNeher2013, author = {Pingel, P. and Neher, Dieter}, title = {Comprehensive picture of p-type doping of P3HT with the molecular acceptor F(4)TCNQ}, series = {Physical review : B, Condensed matter and materials physics}, volume = {87}, journal = {Physical review : B, Condensed matter and materials physics}, number = {11}, publisher = {American Physical Society}, address = {College Park}, issn = {1098-0121}, doi = {10.1103/PhysRevB.87.115209}, pages = {9}, year = {2013}, abstract = {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}, language = {en} } @article{VossBolhuisFeweretal.2013, author = {Voss, Bj{\"o}rn and Bolhuis, Henk and Fewer, David P. and Kopf, Matthias and M{\"o}ke, Fred and Haas, Fabian and El-Shehawy, Rehab and Hayes, Paul and Bergman, Birgitta and Sivonen, Kaarina and Dittmann-Th{\"u}nemann, Elke and Scanlan, Dave J. and Hagemann, Martin and Stal, Lucas J. and Hess, Wolfgang R.}, title = {Insights into the physiology and ecology of the brackish-water-adapted cyanobacterium nodularia spumigena CCY9414 based on a genome-transcriptome analysis}, series = {PLoS one}, volume = {8}, journal = {PLoS one}, number = {3}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0060224}, pages = {22}, year = {2013}, abstract = {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.}, language = {en} } @article{KarpuzCevikKoppitzetal.2013, author = {Karpuz, Eylem Guzel and Cevik, Ahmet Sinan and Koppitz, J{\"o}rg and Cangul, Ismail Naci}, title = {Some fixed-point results on (generalized) Bruck-Reilly *-extensions of monoids}, series = {Fixed point theory and applications}, journal = {Fixed point theory and applications}, number = {3}, publisher = {Springer}, address = {Cham}, issn = {1687-1812}, doi = {10.1186/1687-1812-2013-78}, pages = {9}, year = {2013}, abstract = {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.}, language = {en} } @article{CostaFoersterdeAraujoetal.2013, author = {Costa, Alexandre Cunha and F{\"o}rster, Saskia and de Araujo, Jose Carlos and Bronstert, Axel}, title = {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}, series = {Hydrological processes}, volume = {27}, journal = {Hydrological processes}, number = {7}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1099-1085}, doi = {10.1002/hyp.9243}, pages = {1046 -- 1060}, year = {2013}, abstract = {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.}, language = {en} } @article{DodooBalzerHugeletal.2013, author = {Dodoo, Samuel and Balzer, Bizan N. and Hugel, Thorsten and Laschewsky, Andr{\´e} and von Klitzing, Regine}, title = {Effect of ionic strength and layer number on swelling of polyelectrolyte multilayers in water vapour}, series = {Soft materials}, volume = {11}, journal = {Soft materials}, number = {2}, publisher = {Taylor \& Francis Group}, address = {Philadelphia}, issn = {1539-445X}, doi = {10.1080/1539445X.2011.607203}, pages = {157 -- 164}, year = {2013}, abstract = {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.}, language = {en} }