14,227 research outputs found

    Education as event: a conversation with John D. Caputo by T. Wilson Dickinson

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    This interview with John D. Caputo conducted by T. Wilson Dickinson discusses the implications of the event for the philosophy of education. It addresses various aporias the event poses for academic standards, protocols of writing, teaching as formation or transformation, the post-secular, the new technologies, the old versus the new asceticism in the face of the environmental crisis

    Novel sulfur and selenium containing bis-α-amino acids from 4-hydroxyproline

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    The synthesis of new substituted prolines carrying at C-4 a second α-amino acid residue is reported. The amino acid, l-cysteine or l-selenocysteine, is linked to the proline ring through the sulfur or the selenium atom, respectively. The products were prepared with different stereochemistry at C-4, in few and clean high-yielding steps, with suitable protections for solid phase applications. The introduction of both sulfur and selenium atoms at C-4 of the proline ring seems to enhance significantly the cis geometry at the prolyl amide bond

    "Straßenjugend" als Risikogruppe. Ein Überblick zu den Forschungen im englischsprachigen Kanada

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    Der vorliegende Beitrag gibt einen kurzen Überblick über die angewandte Forschung zum Thema "Straßenjugendliche" und Ausreißer/innen, die während der letzten zwei Jahrzehnte im englischsprachigen Teil Kanadas durchgeführt wurde, sowie über ausgewählte Arbeiten insbesondere aus den USA. Diese Gruppe verdient besondere Aufmerksamkeit, weil sie typischerweise in höchstem Maße gefährdet ist und öffentlich sichtbare Risikojugendliche umfasst. Die konzeptionellen und theoretischen Fragestellungen sowie die Herausforderungen, die sich bei der Formulierung einer brauchbaren Definition von "Straßenjugend" ergeben, werden einer eingehenden Analyse unterzogen. Schließlich wird auf die gängigen Debatten in der Literatur zu den veränderten Konzeptualisierungen von Kindern und Kindheit sowie auf die Implikationen dieser Entwicklungen für die künftige Forschung im Bereich Risikojugendliche und "Straßenjugendliche" eingegangen. (DIPF/Orig.

    Pulsation Period Changes as a Tool to Identify Pre-Zero Age Horizontal Branch Stars

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    One of the most dramatic events in the life of a low-mass star is the He flash, which takes place at the tip of the red giant branch (RGB) and is followed by a series of secondary flashes before the star settles into the zero-age horizontal branch (ZAHB). Yet, no stars have been positively identified in this key evolutionary phase, mainly for two reasons: first, this pre-ZAHB phase is very short compared to other major evolutionary phases in the life of a star; and second, these pre-ZAHB stars are expected to overlap the loci occupied by asymptotic giant branch (AGB), HB and RGB stars observed in the color-magnitude diagram (CMD). We investigate the possibility of detecting these stars through stellar pulsations, since some of them are expected to rapidly cross the Cepheid/RR Lyrae instability strip in their route from the RGB tip to the ZAHB, thus becoming pulsating stars along the way. As a consequence of their very high evolutionary speed, some of these stars may present anomalously large period change rates. We constructed an extensive grid of stellar models and produced pre-ZAHB Monte Carlo simulations appropriate for the case of the Galactic globular cluster M3 (NGC 5272), where a number of RR Lyrae stars with high period change rates are found. Our results suggest that some -- but certainly not all -- of the RR Lyrae stars in M3 with large period change rates are in fact pre-ZAHB pulsators.Comment: Conference Proceedings HELAS Workshop on 'Synergies between solar and stellar modelling', Rome, June 2009, Astrophys. Space Sci., in the pres

    Wetting of gradient fields: pathwise estimates

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    We consider the wetting transition in the framework of an effective interface model of gradient type, in dimension 2 and higher. We prove pathwise estimates showing that the interface is localized in the whole thermodynamically-defined partial wetting regime considered in earlier works. Moreover, we study how the interface delocalizes as the wetting transition is approached. Our main tool is reflection positivity in the form of the chessboard estimate.Comment: Some typos removed after proofreading. Version to be published in PTR

    Triggering the Formation of Halo Globular Clusters with Galaxy Outflows

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    We investigate the interactions of high-redshift galaxy outflows with low-mass virialized (Tvir < 10,000K) clouds of primordial composition. While atomic cooling allows star formation in larger primordial objects, such "minihalos" are generally unable to form stars by themselves. However, the large population of high-redshift starburst galaxies may have induced widespread star formation in these objects, via shocks that caused intense cooling both through nonequilibrium H2 formation and metal-line emission. Using a simple analytic model, we show that the resulting star clusters naturally reproduce three key features of the observed population of halo globular clusters (GCs). First, the 10,000 K maximum virial temperature corresponds to the ~ 10^6 solar mass upper limit on the stellar mass of GCs. Secondly, the momentum imparted in such interactions is sufficient to strip the gas from its associated dark matter halo, explaining why GCs do not reside in dark matter potential wells. Finally, the mixing of ejected metals into the primordial gas is able to explain the ~ 0.1 dex homogeneity of stellar metallicities within a given GC, while at the same time allowing for a large spread in metallicity between different clusters. To study this possibility in detail, we use a simple 1D numerical model of turbulence transport to simulate mixing in cloud-outflow interactions. We find that as the shock shears across the side of the cloud, Kelvin-Helmholtz instabilities arise, which cause mixing of enriched material into > 20% of the cloud. Such estimates ignore the likely presence of large-scale vortices, however, which would further enhance turbulence generation. Thus quantitative mixing predictions must await more detailed numerical studies.Comment: 21 pages, 11 figures, Apj in pres

    Expatriates managers' cultural intelligence as promoter of knowledge transfer in multinational companies

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    This study analyzes the role of the Cultural Intelligence (CQ) of expatriate managers in the processes of Conventional (CKT) and Reverse Knowledge Transfer (RKT) in Multinational Companies (MNCs). The Partial Least Squares-Structural Equation Modeling (PLS-SEM) technique was adopted to analyze the data from a survey of 103 senior expatriate managers working in Croatia. The study reveals how CQ, in all of its four dimensions (metacognitive, cognitive, behavioral, and motivational), acts as a knowledge de-codification and codification filter, assisting managers in the Knowledge Transfer process. The study also reveals how previous international experience does not moderate the positive effect of CQ on both CKT and RKT, offering important theoretical and practical insights to support MNCs in the KT process

    The role of geographical distance on the relationship between cultural intelligence and knowledge transfer

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    Purpose: This paper's purpose is to investigate the ways in which the geographical distance between headquarters and subsidiaries moderates the relationship between cultural intelligence and the knowledge transfer process. Design/methodology/approach: A sample of 103 senior expatriate managers working in Croatia from several European and non-European countries was used to test the hypotheses. Data were collected using questionnaires, while the methodology employed to test the relationship between the variables was Partial least square. Furthermore, interaction-moderation effect was utilised to test the impact of geographical distance and, for testing control variables, Partial least square multigroup analysis was used. Findings: Cultural Intelligence plays a significant role in the knowledge transfer process performance. However, geographical distance has the power to moderate this relationship based on the direction of knowledge transfer. In conventional knowledge transfer, geographical distance has no significant impact. On the contrary, data have shown that, in reverse knowledge transfer, geographical distance has a moderately relevant effect. We supposed that these findings could be connected to the specific location of the knowledge produced by subsidiaries. Practical implications: Multinational companies should take into consideration that the further away a subsidiary is from the headquarters, and the varying difference between cultures, cannot be completely mitigated by the ability of the manager to deal with cultural differences, namely cultural intelligence. Thus, multinational companies need to allocate resources to facilitate the knowledge transfer between subsidiaries. Originality/value: The present study stresses the importance of cultural intelligence in the knowledge transfer process, opening up a new stream of research inside these two areas of research

    Creep, Relaxation and Viscosity Properties for Basic Fractional Models in Rheology

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    The purpose of this paper is twofold: from one side we provide a general survey to the viscoelastic models constructed via fractional calculus and from the other side we intend to analyze the basic fractional models as far as their creep, relaxation and viscosity properties are considered. The basic models are those that generalize via derivatives of fractional order the classical mechanical models characterized by two, three and four parameters, that we refer to as Kelvin-Voigt, Maxwell, Zener, anti-Zener and Burgers. For each fractional model we provide plots of the creep compliance, relaxation modulus and effective viscosity in non dimensional form in terms of a suitable time scale for different values of the order of fractional derivative. We also discuss the role of the order of fractional derivative in modifying the properties of the classical models.Comment: 41 pages, 8 figure
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