851 research outputs found

    Contact and cooperation in the Belgian fertility and family survey.

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    Cooperation; Fertility and family survey;

    Performance of likelihood-based estimation methods for multilevel binary regression models.

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    By means of a fractional factorial simulation experiment, we. compare the performance of penalised quasi-likelihood (PQL), non-adaptive Gaussian quadrature and adaptive Gaussian quadrature in estimating parameters for multilevel logistic regression models. The comparison is done in terms of bias, mean-squared error (MSE), numerical convergence and computational efficiency. It turns out that in terms of MSE, standard versions of the quadrature methods per-form relatively poorly in comparison with PQL.Bias; Binary regression; Convergence; Efficiency; Factorial; Fractional factorial experiment; Gaussian quadrature; Logistic regression; Methods; Model; Models; Monte Carlo simulation; Multilevel analysis; Parameters; Penalised quasi-likelihood; Performance; Regression; Simulation;

    Hydrodynamic lift of vesicles under shear flow in microgravity

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    The dynamics of a vesicle suspension in a shear flow between parallel plates has been investigated under microgravity conditions, where vesicles are only submitted to hydrodynamic effects such as lift forces due to the presence of walls and drag forces. The temporal evolution of the spatial distribution of the vesicles has been recorded thanks to digital holographic microscopy, during parabolic flights and under normal gravity conditions. The collected data demonstrates that vesicles are pushed away from the walls with a lift velocity proportional to γ˙R3/z2\dot{\gamma} R^3/z^2 where γ˙\dot{\gamma} is the shear rate, RR the vesicle radius and zz its distance from the wall. This scaling as well as the dependence of the lift velocity upon vesicle aspect ratio are consistent with theoretical predictions by Olla [J. Phys. II France {\bf 7}, 1533--1540 (1997)].Comment: 6 pages, 8 figure

    A stochastic movement simulator improves estimates of landscape connectivity

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    Acknowledgments This publication issued from the project TenLamas funded by the French Ministère de l'Energie, de l'Ecologie, du Développement Durable et de la Mer through the EU FP6 BiodivERsA Eranet; by the Agence Nationale de la Recherche (ANR) through the open call INDHET and 6th extinction MOBIGEN to V. M. Stevens, M. Baguette, and A. Coulon, and young researcher GEMS (ANR-13-JSV7-0010-01) to V. M. Stevens and M. Baguette; and by a VLIR-VLADOC scholarship awarded to J. Aben. L. Lens, J. Aben, D. Strubbe, and E. Matthysen are grateful to the Research Foundation Flanders (FWO) for financial support of fieldwork and genetic analysis (grant G.0308.13). V. M. Stevens and M. Baguette are members of the “Laboratoire d'Excellence” (LABEX) entitled TULIP (ANR-10-LABX-41). J. M. J. Travis and S. C. F. Palmer also acknowledge the support of NERC. A. Coulon and J. Aben contributed equally to the work.Peer reviewedPublisher PD

    Micro-Capsules in Shear Flow

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    This paper deals with flow-induced shape transitions of elastic capsules. The state of the art concerning both theory and experiments is briefly reviewed starting with dynamically induced small deformation of initially spherical capsules and the formation of wrinkles on polymerized membranes. Initially non-spherical capsules show tumbling and tank-treading motion in shear flow. Theoretical descriptions of the transition between these two types of motion assuming a fixed shape are at variance with the full capsule dynamics obtained numerically. To resolve the discrepancy, we expand the exact equations of motion for small deformations and find that shape changes play a dominant role. We classify the dynamical phase transitions and obtain numerical and analytical results for the phase boundaries as a function of viscosity contrast, shear and elongational flow rate. We conclude with perspectives on timedependent flow, on shear-induced unbinding from surfaces, on the role of thermal fluctuations, and on applying the concepts of stochastic thermodynamics to these systems.Comment: 34 pages, 15 figure

    Українська піснетворчість північно-західного Надкубання

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    Folk singing tradition of the Kuban especially its Ukrainian folk archive create one of the most representative spheres of the musical art of the Russian Federation. We made special expeditions in1990-1996 in order to collect Ukrainian folk songs of various genres in the historical living og Ukrainians in ex-Chornomorya lend. The collected materials can be divided into three types: epic, lyric, ritual. Among those types we figure out such genres: narratives, quazi-narratives, ritual songs of the calendar cycle, ritual songs of the family cycle, lyrical songs. All the collected texts are described in this article with the goal to show that they are functioning as a part of Ukrainian folk tradition within Russian cultural territory. The choir and individual singing are described as a sing of the state of singing performing tradition in contemporary Chornomorya. Authors give a detailed description of the particular performers, their styles and repertoire. Such deep research of the singing tradition of the Ukrainians living in Kuban gives the chance to look at these materials not only as cultural event but also like at the event social and historical meaning

    Quantum Fluctuation Relations for the Lindblad Master Equation

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    An open quantum system interacting with its environment can be modeled under suitable assumptions as a Markov process, described by a Lindblad master equation. In this work, we derive a general set of fluctuation relations for systems governed by a Lindblad equation. These identities provide quantum versions of Jarzynski-Hatano-Sasa and Crooks relations. In the linear response regime, these fluctuation relations yield a fluctuation-dissipation theorem (FDT) valid for a stationary state arbitrarily far from equilibrium. For a closed system, this FDT reduces to the celebrated Callen-Welton-Kubo formula

    Murder in Jerba : honour, shame and hospitality among Maltese in Ottoman Tunisia

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    Little is known about the sizeable Maltese communities developing along the southern and eastern shores of the Mediterranean in the mid-nineteenth century and the extent to which the migrants reproduced Maltese cultural traditions and practices overseas. This article considers this question through a microhistorical analysis of events culminating in the murder of a Maltese woman in the Ottoman Regency of Tunis in 1866. A close reading of transcripts from the interrogation of witnesses and the accused, all members of a Maltese community in Jerba reveals their shared cultural practices and beliefs surrounding the provision of hospitality, honour and shame. Viewed from this perspective, the curious responses of the witnesses to the murder of their compatriot become meaningful, and the crime is reframed as an honour killing.peer-reviewe
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