363 research outputs found

    Detection of fixed points in spatiotemporal signals by clustering method

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    We present a method to determine fixed points in spatiotemporal signals. A 144-dimensioanl simulated signal, similar to a Kueppers-Lortz instability, is analyzed and its fixed points are reconstructed.Comment: 3 pages, 3 figure

    Development of the State Optimism Measure

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    Background Optimism, or positive expectations about the future, is associated with better health. It is commonly assessed as a trait, but it may change over time and circumstance. Accordingly, we developed a measure of state optimism. Methods An initial 29-item pool was generated based on literature reviews and expert consultations. It was administered to three samples: sample 1 was a general healthy population (n = 136), sample 2 was people with cardiac disease (n = 96), and sample 3 was persons recovering from problematic substance use (n = 265). Exploratory factor analysis and item-level descriptive statistics were used to select items to form a unidimensional State Optimism Measure (SOM). Confirmatory factor analysis (CFA) was performed to test fit. Results The selected seven SOM items demonstrated acceptable to high factor loadings on a single dominant factor (loadings: 0.64–0.93). There was high internal reliability across samples (Cronbach\u27s alphas: 0.92–0.96), and strong convergent validity correlations in hypothesized directions. The SOM\u27s correlations with other optimism measures indicate preliminary construct validity. CFA statistics indicated acceptable fit of the SOM model. Conclusions We developed a psychometrically-sound measure of state optimism that can be used in various settings. Predictive and criterion validity will be tested in future studies

    Development of a GEM-TPC prototype

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    The use of GEM foils for the amplification stage of a TPC instead of a con- ventional MWPC allows one to bypass the necessity of gating, as the backdrift is suppressed thanks to the asymmetric field configuration. This way, a novel continuously running TPC, which represents one option for the PANDA central tracker, can be realized. A medium sized prototype with a diameter of 300 mm and a length of 600 mm will be tested inside the FOPI spectrometer at GSI using a carbon or lithium beam at intermediate energies (E = 1-3AGeV). This detector test under realistic experimental conditions should allow us to verify the spatial resolution for single tracks and the reconstruction capability for displaced vertexes. A series of physics measurement implying pion beams is scheduled with the FOPI spectrometer together with the GEM-TPC as well.Comment: 5 pages, 4 figures, Proceedings for 11th ICATTP conference in como (italy

    Draft Genomes, Phylogenetic Reconstruction, and Comparative Genomics of Two Novel Cohabiting Bacterial Symbionts Isolated from Frankliniella occidentalis

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    Obligate bacterial symbionts are widespread in many invertebrates, where they are often confined to specialized host cells and are transmitted directly from mother to progeny. Increasing numbers of these bacteria are being characterized but questions remain about their population structure and evolution. Here we take a comparative genomics approach to investigate two prominent bacterial symbionts (BFo1 and BFo2) isolated from geographically separated populations of western flower thrips, Frankliniella occidentalis. Our multifaceted approach to classifying these symbionts includes concatenated multilocus sequence analysis (MLSA) phylogenies, ribosomal multilocus sequence typing (rMLST), construction of whole-genome phylogenies, and in-depth genomic comparisons. We showed that the BFo1 genome clusters more closely to species in the genus Erwinia, and is a putative close relative to Erwinia aphidicola. BFo1 is also likely to have shared a common ancestor with Erwinia pyrifoliae/Erwinia amylovora and the nonpathogenic Erwinia tasmaniensis and genetic traits similar to Erwinia billingiae. The BFo1 genome contained virulence factors found in the genus Erwinia but represented a divergent lineage. In contrast, we showed that BFo2 belongs within the Enterobacteriales but does not group closely with any currently known bacterial species. Concatenated MLSA phylogenies indicate that it may have shared a common ancestor to the Erwinia and Pantoea genera, and based on the clustering of rMLST genes, it was most closely related to Pantoea ananatis but represented a divergent lineage. We reconstructed a core genome of a putative common ancestor of Erwinia and Pantoea and compared this with the genomes of BFo bacteria. BFo2 possessed none of the virulence determinants that were omnipresent in the Erwinia and Pantoea genera. Taken together, these data are consistent with BFo2 representing a highly novel species that maybe related to known Pantoea

    Design, Fabrication, and Testing of Silicon-integrated Li-ion Secondary Micro Batteries with Interdigital Electrodes

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    This paper reports the design, fabrication, and testing of silicon-integrated lithium ion secondary micro batteries with a side-by-side electrode setup. Cavities separated by narrow silicon spacers served as containments for two interdigitally arranged electrodes and were etched into -Si by wet chemical etching. The etched silicon battery containments were passivated by a layer of SiOx/SixNy. Al current collectors were applied by sputtering and back etching. A volumetric micro dispenser served to fill the cavities with slurries of the active materials - lithium cobalt manganese oxide (Liy(Ni1/2Co1/5Mn3/10)O2) as the cathode and lithium titanate (Li4Ti5O12) as the anode material. Filling with electrolyte, encapsulation, and electrochemical characterization of the finished cells took place in an Ar-filled glove box. The fabricated batteries with IDE show considerably lower impedances than cells with single side by side electrodes and are capable of constant current loads up to 10 C. A linear capacity loss rate of <0.1% per cycle was observed over 30 full cycles at 0.2C

    Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised proton

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    Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off transversely polarised protons are presented. The results were obtained using all the available COMPASS proton data, which were taken in the years 2007 and 2010. The Collins asymmetries exhibit in the valence region a non-zero signal for pions and there are hints of non-zero signal also for kaons. The Sivers asymmetries are found to be positive for positive pions and kaons and compatible with zero otherwise.Comment: 15 pages, 13 figures and 1 tabl

    Measurement of the charged-pion polarisability

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    The COMPASS collaboration at CERN has investigated pion Compton scattering, πγπγ\pi^-\gamma\rightarrow \pi^-\gamma, at centre-of-mass energy below 3.5 pion masses. The process is embedded in the reaction πNiπγ  Ni\pi^-\mathrm{Ni}\rightarrow\pi^-\gamma\;\mathrm{Ni}, which is initiated by 190\,GeV pions impinging on a nickel target. The exchange of quasi-real photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, Q2<0.0015Q^2<0.0015\,(GeV/cc)2^2. From a sample of 63\,000 events the pion electric polarisability is determined to be $\alpha_\pi\ =\ (\,2.0\ \pm\ 0.6_{\mbox{\scriptsize stat}}\ \pm\ 0.7_{\mbox{\scriptsize syst}}\,) \times 10^{-4}\,\mbox{fm}^3undertheassumption under the assumption \alpha_\pi=-\beta_\pi$, which relates the electric and magnetic dipole polarisabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction, that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambigiously known, was performed for an independent estimate of the systematic uncertainty.Comment: Published version: 9 pages, 3 figures, 1 tabl

    Spin alignment and violation of the OZI rule in exclusive ω\omega and ϕ\phi production in pp collisions

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    Exclusive production of the isoscalar vector mesons ω\omega and ϕ\phi is measured with a 190 GeV/c/c proton beam impinging on a liquid hydrogen target. Cross section ratios are determined in three intervals of the Feynman variable xFx_{F} of the fast proton. A significant violation of the OZI rule is found, confirming earlier findings. Its kinematic dependence on xFx_{F} and on the invariant mass MpVM_{p\mathrm{V}} of the system formed by fast proton pfastp_\mathrm{fast} and vector meson VV is discussed in terms of diffractive production of pfastVp_\mathrm{fast}V resonances in competition with central production. The measurement of the spin density matrix element ρ00\rho_{00} of the vector mesons in different selected reference frames provides another handle to distinguish the contributions of these two major reaction types. Again, dependences of the alignment on xFx_{F} and on MpVM_{p\mathrm{V}} are found. Most of the observations can be traced back to the existence of several excited baryon states contributing to ω\omega production which are absent in the case of the ϕ\phi meson. Removing the low-mass MpVM_{p\mathrm{V}} resonant region, the OZI rule is found to be violated by a factor of eight, independently of xFx_\mathrm{F}.Comment: 23 pages, 13 figures and 5 table

    Search for exclusive photoproduction of Zc±_c^{\pm}(3900) at COMPASS

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    A search for the exclusive production of the Zc±(3900)Z_c^{\pm}(3900) hadron by virtual photons has been performed in the channel Zc±(3900)J/ψπ±Z_c^{\pm}(3900)\rightarrow J/\psi \pi^{\pm}. The data cover the range from 7 GeV to 19 GeV in the centre-of-mass energy of the photon-nucleon system. The full set of the COMPASS data set collected with a muon beam between 2002 and 2011 has been used. An upper limit for the ratio BR(Zc±(3900)J/ψπ±)×σγ NZc±(3900) N/σγ NJ/ψ NBR(Z_c^{\pm}(3900)\rightarrow J/\psi \pi^{\pm} )\times \sigma_{ \gamma~N \rightarrow Z_c^{\pm}(3900)~ N} /\sigma_{\gamma~N \rightarrow J/\psi~ N} of 3.7×1033.7\times10^{-3} has been established at the confidence level of 90%.Comment: 8 pages, 3 figures, 1 tabl

    The functional repertoire contained within the native microbiota of the model nematode Caenorhabditis elegans

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    The microbiota is generally assumed to have a substantial influence on the biology of multicellular organisms. The exact functional contributions of the microbes are often unclear and cannot be inferred easily from 16S rRNA genotyping, which is commonly used for taxonomic characterization of bacterial associates. In order to bridge this knowledge gap, we here analyzed the metabolic competences of the native microbiota of the model nematode Caenorhabditis elegans. We integrated whole-genome sequences of 77 bacterial microbiota members with metabolic modeling and experimental characterization of bacterial physiology. We found that, as a community, the microbiota can synthesize all essential nutrients for C. elegans. Both metabolic models and experimental analyses revealed that nutrient context can influence how bacteria interact within the microbiota. We identified key bacterial traits that are likely to influence the microbe’s ability to colonize C. elegans (i.e., the ability of bacteria for pyruvate fermentation to acetoin) and affect nematode fitness (i.e., bacterial competence for hydroxyproline degradation). Considering that the microbiota is usually neglected in C. elegans research, the resource presented here will help our understanding of this nematode’s biology in a more natural context. Our integrative approach moreover provides a novel, general framework to characterize microbiota-mediated functions
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