3,351 research outputs found
Brentano’s lectures on positivism (1893-1894) and his relationship to Ernst Mach
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
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
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?
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
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 ; for small , 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
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
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
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
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
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
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 or larger. The measurement of the
-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
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