2,195 research outputs found

    Chiral quark-soliton model in the Wigner-Seitz approximation

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    In this paper we study the modification of the properties of the nucleon in the nucleus within the quark-soliton model. This is a covariant, dynamical model, which provides a non-linear representation of the spontaneously broken SU(2)_L X SU(2)_R symmetry of QCD. The effects of the nuclear medium are accounted for by using the Wigner-Seitz approximation and therefore reducing the complex many-body problem to a simpler single-particle problem. We find a minimum in the binding energy at finite density, a change in the isoscalar nucleon radius and a reduction of the in-medium pion decay constant. The latter is consistent with a partial restoration of chiral symmetry at finite density, which is predicted by other models.Comment: 30 pages, 13 figures; uses REVTeX and epsfi

    Charge form factor of π\pi and KK mesons

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    The charge form factor of π\pi and KK mesons is evaluated adopting a relativistic constituent quark model based on the light-front formalism. The relevance of the high-momentum components of the meson wave function, for values of the momentum transfer accessible to CEBAFCEBAF energies, is illustrated. The predictions for the elastic form factor of π\pi and KK mesons are compared with the results of different relativistic approaches, showing that the measurements of the pion and kaon form factors planned at CEBAFCEBAF could provide information for discriminating among various models of the meson structure.Comment: 8 pages, latex, 4 figures available as separate .uu fil

    Sensory Measurements: Coordination and Standardization

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    Do sensory measurements deserve the label of “measurement”? We argue that they do. They fit with an epistemological view of measurement held in current philosophy of science, and they face the same kinds of epistemological challenges as physical measurements do: the problem of coordination and the problem of standardization. These problems are addressed through the process of “epistemic iteration,” for all measurements. We also argue for distinguishing the problem of standardization from the problem of coordination. To exemplify our claims, we draw on olfactory performance tests, especially studies linking olfactory decline to neurodegenerative disorders

    The Kinematics, Metallicities, and Orbits of Six Recently Discovered Galactic Star Clusters with Magellan/M2FS Spectroscopy

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    We present Magellan/M2FS spectroscopy of four recently discovered Milky Way star clusters (Gran 3, Gran 4, Garro 01, LP 866) and two newly discovered open clusters (Gaia 9, Gaia 10) at low Galactic latitudes. We measure line-of-sight velocities and stellar parameters ([Fe/H], logg\log{g}, TeffT_{\rm eff}, [Mg/Fe]) from high resolution spectroscopy centered on the Mg triplet and identify 20-80 members per star cluster. We determine the kinematics and chemical properties of each cluster and measure the systemic proper motion and orbital properties by utilizing Gaia astrometry. We find Gran 3 to be an old, metal-poor (mean metallicity of [Fe/H]=-1.84) globular cluster located in the Galactic bulge on a retrograde orbit. Gran 4 is an old, metal-poor ([Fe/H]}=-1.84) globular cluster with a halo-like orbit that happens to be passing through the Galactic plane. The orbital properties of Gran 4 are consistent with the proposed LMS-1/Wukong and/or Helmi streams merger events. Garro 01 is an old, metal-rich ([Fe/H]=-0.30) globular cluster on a near circular orbit in the outer disk. Gaia 9 and Gaia 10 are among the most distant known open clusters at RGC18,21.2 kpcR_{GC}\sim 18, 21.2~kpc and most metal-poor with [Fe/H]~-0.50,-0.46 for Gaia 9 and Gaia 10, respectively. LP 866 is a nearby, metal-rich open cluster ([Fe/H]=+0.1=+0.1). The discovery and confirmation of multiple star clusters in the Galactic plane shows the power of {\it Gaia} astrometry and the star cluster census remains incomplete.Comment: 19 pages, 15 figures, submitted to MNRAS, associated data products available at https://doi.org/10.5281/zenodo.780912

    Anxiety and self-esteem as mediators of the relation between family communication and indecisiveness in adolescence

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    Abstract In this study, we explored the unique and common contributions of anxiety, self-esteem, and family communication on indecisiveness among adolescents. Three hundred and fifty pupils from 13 to 16 years of age completed selfreport measures on indecisiveness, quality of family communication, trait anxiety, and self-esteem. The findings in this study showed that students\u2019 indecisiveness is predicted by family communication mediated by anxiety and self-esteem. These results have important implications for practice as it stresses the importance of anxiety and self-esteem. Nevertheless, the counselors could also focus on enhancing relationship-building skills by introducing the adolescents\u2019 career formation as an adolescent\u2013parent joint project.L\u2019anxie\ub4te\ub4 et l\u2019estime de soi comme me\ub4diateurs de la relation entre communication au sein de la famille et indecision chronique a` l\u2019adolescence. Dans cette e\ub4tude, nous avons explore\ub4 les contributions uniques et communes de l\u2019anxiete\ub4, de l\u2019estime de soi et de la communication au sein de la famille sur l\u2019indecision chronique aupres d\u2019adolescents. Trois cent cinquante e\ub4le`ves a\u2c6ge\ub4s de 13 a` 16 ans ont rempli des mesures d\u2019auto-e\ub4valuation de l\u2019inde\ub4cision chronique, de la qualite\ub4 de la communication familiale, de l\u2019anxie\ub4te\ub4-trait et de l\u2019estime de soi. Les re\ub4sultats de cette e\ub4tude ont montre\ub4 que l\u2019inde\ub4cision des e\ub4tudiants est explique\ub4e par la communication au sein de la famille et que ce lien est me\ub4diatise\ub4 par l\u2019anxie\ub4te\ub4 et l\u2019estime de soi. Ces re\ub4sultats ont des implications importantes pour la pratique car ils soulignent l\u2019importance de l\u2019anxie\ub4te\ub4 et l\u2019estime de soi. Ne\ub4anmoins, les conseillers pourraient e\ub4galement se concentrer sur l\u2019ame\ub4lioration des compe\ub4tences de construction relationnelle en introduisant la formation professionnelle des adolescents comme un projet conjoint adolescent-parent.Resumen. Ansiedad y Autoestima como Mediadores de la Relacio\ub4n entre Comunicacio\ub4n Familiar e Indecisio\ub4n en la Adolescencia. En este estudio, exploramos las contribuciones u\ub4nicas y comunes de la ansiedad, la autoestima y la comunicacio\ub4n de familia en la indecisio\ub4n de los adolescentes. Tres y cientos cincuenta alumnos entre los 13 y 16 an\u2dcos completaron auto-evaluaciones sobre la indecisio\ub4n, la calidad de comunicacio\ub4n familiar, los rasgos de ansiedad y la autoestima. Los resultados en este estudio muestran que la indecisio\ub4n en los estudiantes es prevista por la comunicacio\ub4n familiar mediada por la ansiedad y la autoestima. Estos resultados tiene importantes implicaciones para la practica ya que destacan la importancia de la ansiedad y la autoestima. Sin embargo, los consejeros podr\u131\ub4an tambie\ub4n focalizarse en el aumento de sus habilidades para construir relaciones mediante la introduccio\ub4n de la formacio\ub4n profesional para adolescentes como un proyecto conjunto del adolescente-padre.Angst und Selbstwertgefu\ua8 hl als Mediatoren der Beziehung zwischen Kommunikation in der Familie und Unentschlossenheit in der Adoleszenz. In dieser Studie untersuchten wir die spezifischen und gemeinsamen Beitra\ua8ge von Angst, Selbstwertgefu\ua8hl und Kommunikation in der Familie auf Unentschlossenheit unter Jugendlichen. Dreihundertfu\ua8nfzig Schu\ua8ler, zwischen 13 bis 16 Jahre alt, fu\ua8llten Skalen zur Unentschlossenheit, Qualita\ua8t der Kommunikation in der Familie, A\ua8 ngstlichkeit und Selbstwertgefu\ua8hl aus. Die Ergebnisse dieser Studie zeigten, dass Unentschlossenheit der Schu\ua8ler von Kommunikation in der Familie vorhergesagt wird, vermittelt durch Angst und Selbstwertgefu\ua8 hl. Diese Ergebnisse haben wichtige Implikationen fu\ua8r die Praxis, da sie die Bedeutung von Angst und Selbstwertgefu\ua8hl hervorheben. Dennoch ko\ua8nnten sich die Beratungspersonen durch die Einfu\ua8hrung der beruflichen Bildung der Jugendlichen als ein gemeinsames Projekt von Jugendliche-Elternteil auch auf die Verbesserung der Fa\ua8higkeiten zum Aufbau von Beziehungen konzentrieren

    Bridging topological and functional information in protein interaction networks by short loops profiling

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    Protein-protein interaction networks (PPINs) have been employed to identify potential novel interconnections between proteins as well as crucial cellular functions. In this study we identify fundamental principles of PPIN topologies by analysing network motifs of short loops, which are small cyclic interactions of between 3 and 6 proteins. We compared 30 PPINs with corresponding randomised null models and examined the occurrence of common biological functions in loops extracted from a cross-validated high-confidence dataset of 622 human protein complexes. We demonstrate that loops are an intrinsic feature of PPINs and that specific cell functions are predominantly performed by loops of different lengths. Topologically, we find that loops are strongly related to the accuracy of PPINs and define a core of interactions with high resilience. The identification of this core and the analysis of loop composition are promising tools to assess PPIN quality and to uncover possible biases from experimental detection methods. More than 96% of loops share at least one biological function, with enrichment of cellular functions related to mRNA metabolic processing and the cell cycle. Our analyses suggest that these motifs can be used in the design of targeted experiments for functional phenotype detection.This research was supported by the Biotechnology and Biological Sciences Research Council (BB/H018409/1 to AP, ACCC and FF, and BB/J016284/1 to NSBT) and by the Leukaemia & Lymphoma Research (to NSBT and FF). SSC is funded by a Leukaemia & Lymphoma Research Gordon Piller PhD Studentship

    IONS FOR LHC: STATUS OF THE INJECTOR CHAIN

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    The LHC will, in addition to proton runs, be operated with Pb ions and provide collisions at energies of 5.5 TeV per nucleon pair, i.e. more than 1.1 PeV per event, to experiments. The transformation of CERN's ion injector complex (Linac3-LEIR-PS-SPS) to allow collision of ions in LHC in 2008 is well under way. The status of these modifications and the latest results of commissioning will be presented. The remaining challenges are reviewed
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