366 research outputs found

    Good refugees, bad migrants? Intergroup helping orientations towards refugees, migrants and economic migrants in Germany

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    The present study examined the effect of group labels on helping behavioral intentions toward displaced people in Germany. Specifically, it examined the impact of different labels evoking either voluntary or forced migration (i.e., migrants, economic migrants, and refugees) on different helping orientations (e.g., dependency vs. autonomy-ori-ented helping) and if these effects occur via perceived intergroup threat, warmth and competence stereotypes. Participants (N = 304) were randomly assigned to one of three conditions (refugee vs. migrant vs. economic migrant) and read fabricated case vignettes, featuring a displaced person who arrived in Germany recently. Results showed that, as predicted, the use of different group labels affected the helping ori-entations of host society members, as well as, the stereotypes they held. No signifi-cant label effects were found for intergroup threat. While the label refugee evoked dependency-oriented helping intentions and triggered paternalistic stereotypes, the label economic migrants increased opposition to help, decreased help affirmation and evoked envious stereotypes. Practical implications to strengthen peaceful intergroup relations between host society members and newcomers are discussed.info:eu-repo/semantics/acceptedVersio

    A highly stable atomic vector magnetometer based on free spin precession

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    We present a magnetometer based on optically pumped Cs atoms that measures the magnitude and direction of a 1 μ\muT magnetic field. Multiple circularly polarized laser beams were used to probe the free spin precession of the Cs atoms. The design was optimized for long-time stability and achieves a scalar resolution better than 300 fT for integration times ranging from 80 ms to 1000 s. The best scalar resolution of less than 80 fT was reached with integration times of 1.6 to 6 s. We were able to measure the magnetic field direction with a resolution better than 10 μ\murad for integration times from 10 s up to 2000 s

    Constraining interactions mediated by axion-like particles with ultracold neutrons

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    We report a new limit on a possible short range spin-dependent interaction from the precise measurement of the ratio of Larmor precession frequencies of stored ultracold neutrons and 199^{199}Hg atoms confined in the same volume. The measurement was performed in a \sim1μ\mu T vertical magnetic holding field with the apparatus searching for a permanent electric dipole moment of the neutron at the Paul Scherrer Institute. A possible coupling between freely precessing polarized neutron spins and unpolarized nucleons of the wall material can be investigated by searching for a tiny change of the precession frequencies of neutron and mercury spins. Such a frequency change can be interpreted as a consequence of a short range spin-dependent interaction that could possibly be mediated by axions or axion-like particles. The interaction strength is proportional to the CP violating product of scalar and pseudoscalar coupling constants gSgPg_Sg_P. Our result confirms limits from complementary experiments with spin-polarized nuclei in a model-independent way. Limits from other neutron experiments are improved by up to two orders of magnitude in the interaction range of 106<λ<10410^{-6}<\lambda<10^{-4} m

    Discordant MZ twins With Cleft Lip and Palate: a model for identifying genes in complex traits.

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    Monozygotic (MZ) twins may be discordant for complex traits due to differential environmental exposure in utero, epigenetic variability in imprinting, X chromosome inactivation, or stochastic effects. Occasionally MZ twins may be discordant for chromosomal and single gene disorders due to somatic mosaicism. For complex traits, which are due to the interactive effects of multiple genes and environmental factors, the affected twin of a discordant MZ pair offers the possibility for identifying somatic mutations in candidate genes. DNA sequencing of candidate genes in discordant MZ twins can identify those rare etiologic mutational events responsible for the different phenotypes since the confounding effects of common single nucleotide polymorphisms are eliminated, as DNA sequences should be identical in MZ pairs. In this report we describe the extensive DNA sequencing of 18 candidate genes in a sample of MZ and dizygotic (DZ) twins with nonsyndromic cleft lip with or without cleft palate. We were unable to identify any somatic differences in approximately 34 Kb of DNA sequenced in 13 MZ pairs, for a total of approximately 900 Kb of sequence comparisons, supporting the hypothesis that nonetiologic posttwinning mutations are rare. While no etiologic variants were identified in this study, sequence comparisons of discordant MZ twins can serve as a tool for identifying etiologic mutations in clefting and other complex traits

    Cytosine-to-Uracil Deamination by SssI DNA Methyltransferase

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    The prokaryotic DNA(cytosine-5)methyltransferase M.SssI shares the specificity of eukaryotic DNA methyltransferases (CG) and is an important model and experimental tool in the study of eukaryotic DNA methylation. Previously, M.SssI was shown to be able to catalyze deamination of the target cytosine to uracil if the methyl donor S-adenosyl-methionine (SAM) was missing from the reaction. To test whether this side-activity of the enzyme can be used to distinguish between unmethylated and C5-methylated cytosines in CG dinucleotides, we re-investigated, using a sensitive genetic reversion assay, the cytosine deaminase activity of M.SssI. Confirming previous results we showed that M.SssI can deaminate cytosine to uracil in a slow reaction in the absence of SAM and that the rate of this reaction can be increased by the SAM analogue 5’-amino-5’-deoxyadenosine. We could not detect M.SssI-catalyzed deamination of C5-methylcytosine (m5C). We found conditions where the rate of M.SssI mediated C-to-U deamination was at least 100-fold higher than the rate of m5C-to-T conversion. Although this difference in reactivities suggests that the enzyme could be used to identify C5-methylated cytosines in the epigenetically important CG dinucleotides, the rate of M.SssI mediated cytosine deamination is too low to become an enzymatic alternative to the bisulfite reaction. Amino acid replacements in the presumed SAM binding pocket of M.SssI (F17S and G19D) resulted in greatly reduced methyltransferase activity. The G19D variant showed cytosine deaminase activity in E. coli, at physiological SAM concentrations. Interestingly, the C-to-U deaminase activity was also detectable in an E. coli ung+ host proficient in uracil excision repair

    Measurement of the permanent electric dipole moment of the neutron

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    We present the result of an experiment to measure the electric dipole moment EDM) of the neutron at the Paul Scherrer Institute using Ramsey's method of separated oscillating magnetic fields with ultracold neutrons (UCN). Our measurement stands in the long history of EDM experiments probing physics violating time reversal invariance. The salient features of this experiment were the use of a Hg-199 co-magnetometer and an array of optically pumped cesium vapor magnetometers to cancel and correct for magnetic field changes. The statistical analysis was performed on blinded datasets by two separate groups while the estimation of systematic effects profited from an unprecedented knowledge of the magnetic field. The measured value of the neutron EDM is d_{\rm n} = (0.0\pm1.1_{\rm stat}\pm0.2_{\rmsys})\times10^{-26}e\,{\rm cm}

    Multiplicity and transverse momentum fluctuations in inelastic proton-proton interactions at the CERN Super Proton Synchrotron

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    Measurements of multiplicity and transverse momentum fluctuations of charged particles were performed in inelastic p+p interactions at 20, 31, 40, 80 and 158 GeV/c beam momentum. Results for the scaled variance of the multiplicity distribution and for three strongly intensive measures of multiplicity and transverse momentum fluctuations \$\Delta[P_{T},N]\$, \$\Sigma[P_{T},N]\$ and \$\Phi_{p_T}\$ are presented. For the first time the results on fluctuations are fully corrected for experimental biases. The results on multiplicity and transverse momentum fluctuations significantly deviate from expectations for the independent particle production. They also depend on charges of selected hadrons. The string-resonance Monte Carlo models EPOS and UrQMD do not describe the data. The scaled variance of multiplicity fluctuations is significantly higher in inelastic p+p interactions than in central Pb+Pb collisions measured by NA49 at the same energy per nucleon. This is in qualitative disagreement with the predictions of the Wounded Nucleon Model. Within the statistical framework the enhanced multiplicity fluctuations in inelastic p+p interactions can be interpreted as due to event-by-event fluctuations of the fireball energy and/or volume.Comment: 18 pages, 12 figure

    Influence of the addition of LPG-reformate and H2 on an engine dually fuelled with LPG–diesel, –RME and –GTL Fuels

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    AbstractDual fuel compression ignition engine has been proposed as one approach to reduce diesel engine regulated emissions (NOX and Soot) and to also allow the utilisation of other non-traditional fuels in transportation, in order to improve fuel security and CO2 emissions. In an attempt to improve the combustion characteristics of the LPG–diesel dual fuelled engine the influence of the (a) hydrogen and reformate (H2 and CO) additions and (b) properties of the in-cylinder injected diesel fuel, in this case diesel, biodiesel and synthetic diesel fuel were investigated.Improvements on engine thermal efficiency and HC (including particular HC species) emissions with the reformate and further improvements on CO, soot and particulate matter with hydrogen with respect to LPG–diesel dual fuel combustion were obtained. However, an increase in NOX was obtained due to the high in-cylinder temperature as a result of the shorter advanced premixed combustion. Moreover, the RME’s oxygen content, different injection (i.e. different high bulk modulus) and combustion characteristics as a result of its properties modified the combustion process and hence produced even lower HC, CO, soot and PM emissions. On the other hand, the lower density of GTL has changed the diesel fuel injection and combustion characteristics in dual fuelling mode which resulted in the increased regulated (HC and CO) and unregulated emissions. However, LPG–GTL dual fuelling with reformate and H2 addition showed better smoke-NOX trade-off compared to that of ULSD and RME
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