3,351 research outputs found

    Brentano’s lectures on positivism (1893-1894) and his relationship to Ernst Mach

    Get PDF
    This paper is mainly about Brentano’s commentaries on Ernst Mach in his lectures “Contemporary philosophical questions” which he held one year before he left Austria. I will first identify the main sources of Brentano’s interests in Comte’s and J. S. Mill’s positivism during his Würzburg period. The second section provides a short overview of Brentano’s 1893-1894 lectures and his criticism of Comte, Kirchhoff, and Mill. The next sections bear on Brentano’s criticism of Mach’s monism and Brentano’s argument against the reduction of the mental based on his theory of intentionality. The last section is about Brentano’s proposal to replace the identity relation in Mach’s theory of elements by that of intentional correlation. I conclude with a remark on the history of philosophy in Austria

    Computation of forces in strongly nonlinear magnetic fields using higher-order eggshell algorithm

    Full text link
    A novel version of the eggshell-based procedure for numerical computation of magnetic forces and torques acting on ferromagnetic bodies in highly nonlinear magnetic fields is presented. The procedure works with a fully adaptive higher-order finite element method developed for years in our research group, that is implemented in own code Agros2D and library Hermes. The power of the methodology and both codes is demonstrated on the solution of two typical examples: computation of the static characteristic of a magnetic actuator and torque characteristic of a flux-switched permanent-magnet machine. The results obtained are compared with data calculated by several other available codes

    Common inflammatory mediators orchestrate pathophysiological processes in rheumatoid arthritis and atherosclerosis

    Get PDF
    RA is characterized by a systemic inflammatory state, in which immune cells and soluble mediators play a crucial role. These inflammatory processes resemble those in other chronic inflammatory diseases, such as atherosclerosis. The chronic systemic inflammation in RA can be considered as an independent risk factor for the development of atherosclerosis, and represents an important field to investigate the reasons of the increase of acute cardiovascular events in RA. In the present review, we focused on several mediators of autoimmunity, inflammation and endothelial dysfunction, which can be considered the most promising targets to prevent atherogenesis in RA. Among several mediators, the pro-inflammatory cytokine TNF-α has been shown as a crucial factor to induce atherosclerosis in RA patient

    Leukocyte recruitment in atherosclerosis: Potential targets for therapeutic approaches?

    Get PDF
    Abstract.: Atherosclerosis is a complex inflammatory disease involving cellular migration and interaction. Vascular injury in response to different cardiovascular risk factors enhances endothelial dysfunction, which in turn promotes the expression of inflammatory markers and transendothelial leukocyte migration. Recruitment of leukocytes from the blood stream into the vessel intima is a crucial step for the development of the disease. Recent findings have highlighted the role of chemokines, chemokine receptors, adhesion molecules, and gap junctions in this process by acting as chemoattractant, adhesive, or intercellular communication molecules. In this short review, we summarize new data concerning the different steps from leukocyte arrest to transendothelial migration and discuss potential new therapeutic approaches concerning these processe

    Amplitude control of quantum interference

    Full text link
    Usually, the oscillations of interference effects are controlled by relative phases. We show that varying the amplitudes of quantum waves, for instance by changing the reflectivity of beam splitters, can also lead to quantum oscillations and even to Bell violations of local realism. We first study theoretically a generalization of the Hong-Ou-Mandel experiment to arbitrary source numbers and beam splitter transmittivity. We then consider a Bell type experiment with two independent sources, and find strong violations of local realism for arbitrarily large source number NN; for small NN, one operator measures essentially the relative phase of the sources and the other their intensities. Since, experimentally, one can measure the parity of the number of atoms in an optical lattice more easily than the number itself, we assume that the detectors measure parity.Comment: 4 pages; 4 figure

    On the stability of self-gravitating accreting flows

    Get PDF
    Analytic methods show stability of the stationary accretion of test fluids but they are inconclusive in the case of self-gravitating stationary flows. We investigate numerically stability of those stationary flows onto compact objects that are transonic and rich in gas. In all studied examples solutions appear stable. Numerical investigation suggests also that the analogy between sonic and event horizons holds for small perturbations of compact support but fails in the case of finite perturbations.Comment: 10 pages, accepted for publication in PR

    Internationalisation des élites académiques suisses au 20ème siècle : convergences et contrastes

    Get PDF
    A partir d'une base de données originale sur les professeurs de droit et de sciences économiques des universités suisses sur l'ensemble du XXe siècle, cet article rend compte des diverses dynamiques d'internationalisation de ces élites. Trois enseignements majeurs peuvent être tirés de nos analyses. D'abord, d'un point de vue diachronique, il est possible de diviser le XXe siècle en trois phases historiques : une internationalité forte des élites académiques au début du siècle, une nationalisation ou « relocalisation » suite à la Première Guerre mondiale, puis une « ré-internationalisation » à partir des années 1960 et de manière accélérée depuis les années 1980. Ensuite, les professeurs de sciences économiques, en terme de nationalités ou de lieu de formation, sont plus cosmopolites et ont moins d'ancrage local que leurs homologues juristes. Enfin, la prédominance germanique parmi les professeurs des universités suisses au début du siècle, qui s'explique autant par une internationalité d'« excellence » que de « proximité », laisse place, surtout en sciences économiques, à une montée de l'influence des Etats-Unis, révélatrice d'un effritement de l'internationalité de « proximité »

    Variation of the speed of light with temperature of the expanding universe

    Full text link
    From an extended relativistic dynamics for a particle moving in a cosmic background field with temperature T, we aim to obtain the speed of light with an explicit dependence on the background temperature of the universe. Although finding the speed of light in the early universe much larger than its current value, our approach does not violate the postulate of special relativity. Moreover, it is shown that the high value of the speed of light in the early universe was drastically decreased before the beginning of the inflationary period. So we are led to conclude that the theory of varying speed of light should be questioned as a possible solution of the horizon problem.Comment: 3 pages and 1 figure; Phys. Rev. D86, 027703 (2012

    Phase detection at the quantum limit with multi-photon Mach-Zehnder interferometry

    Get PDF
    We study a Mach-Zehnder interferometer fed by a coherent state in one input port and vacuum in the other. We explore a Bayesian phase estimation strategy to demonstrate that it is possible to achieve the standard quantum limit independently from the true value of the phase shift and specific assumptions on the noise of the interferometer. We have been able to implement the protocol using parallel operation of two photon-number-resolving detectors and multiphoton coincidence logic electronics at the output ports of a weakly-illuminated Mach-Zehnder interferometer. This protocol is unbiased and saturates the Cramer-Rao phase uncertainty bound and, therefore, is an optimal phase estimation strategy.Comment: 4 pages, 5 figures replaced fig. 1 to correct graphics bu

    Phase Estimation from Atom Position Measurements

    Full text link
    We study the measurement of the position of atoms as a means to estimate the relative phase between two Bose-Einstein condensates. First, we consider NN atoms released from a double-well trap, forming an interference pattern, and show that a simple least-squares fit to the density gives a shot-noise limited sensitivity. The shot-noise limit can instead be overcome by using correlation functions of order N\sqrt{N} or larger. The measurement of the NthN\mathrm{th}-order correlation function allows to estimate the relative phase at the Heisenberg limit. Phase estimation through the measurement of the center-of-mass of the interference pattern can also provide sub-shot-noise sensitivity. Finally, we study the effect of the overlap between the two clouds on the phase estimation, when Mach-Zehnder interferometry is performed in a double-well.Comment: 20 pages, 6 figure
    corecore