3,964 research outputs found
Cardiovascular adaptations during long-term altered gravity
Cardiovascular studies were performed on unrestrained, unanesthetized rats and on the same animals in head-down hypokinetic conditions as well as during readaptation of the same animals to free activity. Possible circulatory mechanisms that evolved in mammals during long-lasting gravity exposure are considered. These mechanisms are likely to be affected during exposure to 0-g forces
The Juridical Domain of the Intrinsic Common Good of the Political Community: Hervadian Perspectives
This paper explores the contribution of Javier Hervada to the correct understanding of the juridical domain of the intrinsic common good of the political community. After some introductory remarks on the current status of the intrinsic political common good, in the first part of the article the concept of the intrinsic aspect of the political common good is presented from the viewpoint of the Thomistic social ontology and Catholic social doctrine. In the second part of the article, some crucial Hervadian perspectives are elaborated for the conception of the juridicity of the intrinsic bonum commune of the polity.Este artículo explora la contribución de Javier Hervada a la correcta comprensión del dominio jurídico del bien común intrínseco de la comunidad política. Después de algunas observaciones introductorias sobre el estado actual del bien común político intrínseco, en la primera parte del artículo se presenta el concepto del aspecto intrínseco del bien común político desde el punto de vista de la ontología social tomista y la doctrina social católica. En la segunda parte del artículo se elaboran algunas perspectivas hervadianas cruciales para la concepción de la juridicidad del bonum commune intrínseco de la comunidad política
The Three Levels of Law’s Goodness and then One More: Exploring John Finnis’s Account of Good Juridical Reasons for Action
The article revisits, in the first section, the core arguments of John Finnis’s account of law’s «goodness». Having established that the premises of these arguments are situated in Finnis’s theses on what constitutes good juridical reasons for action, and on law’s «double life», the three levels of law’s goodness are explored in detail. In the second section, the author argues that Aquinas’s juridical philosophy contains another discrete level of juridical goodness relevant to law. This level is then presented along with a critical assessment of its harmony with Finnis’s theory.El artículo revisa, en la primera sección, los argumentos centrales del relato de John Finnis sobre la «bondad» de la ley. Una vez establecido que las premisas de estos argumentos están situadas en las tesis de Finnis sobre lo que constituyen buenas razones jurídicas para la acción, y sobre la «doble vida» de la ley, se exploran en detalle los tres niveles de bondad de la ley. En la segunda sección, el autor argumenta que la filosofía jurídica de Tomás de Aquino contiene otro nivel discreto de bondad jurídica relevante para la ley. Este nivel se presenta junto con una evaluación crítica de su armonía con la teoría de Finnis
The influence of microlensing on the shape of the AGN Fe K-alpha line
We study the influence of gravitational microlensing on the AGN Fe K-alpha
line confirming that unexpected enhancements recently detected in the iron line
of some AGNs can be produced by this effect. We use a ray tracing method to
study the influence of microlensing in the emission coming from a compact
accretion disc considering both geometries, Schwarzschild and Kerr.
Thanks to the small dimensions of the region producing the AGN Fe K-alpha
line, the Einstein Ring Radii associated to even very small compact objects
have size comparable to the accretion disc hence producing noticeable changes
in the line profiles. Asymmetrical enhancements contributing differently to the
peaks or to the core of the line are produced by a microlens, off-centered with
respect to the accretion disc.
In the standard configuration of microlensing by a compact object in an
intervening galaxy, we found that the effects on the iron line are two orders
of magnitude larger than those expected in the optical or UV emission lines. In
particular, microlensing can satisfactorily explain the excess in the iron line
emission found very recently in two gravitational lens systems, H 1413+117 and
MG J0414+0534.
Exploring other physical {scenario} for microlensing, we found that compact
objects (of the order of one Solar mass) which belong to {the bulge or the
halo} of the host galaxy can also produce significant changes in the Fe
K line profile of an AGN. However, the optical depth estimated for
this type of microlensing is {very small, , even in a favorable
case.Comment: Astron. Astrophys. accepte
Influence of Intra-cell Traffic on the Output Power of Base Station in GSM
In this paper we analyze the influence of intracell traffic in a GSM cell on the base station output power. It is proved that intracell traffic increases this power. If offered traffic is small, the increase of output power is equal to the part of intracell traffic. When the offered traffic and, as the result, call loss increase, the increase of output power becomes less. The results of calculation are verified by the computer simulation of traffic process in the GSM cell. The calculation and the simulation consider the uniform distribution of mobile users in the cell, but the conclusions are of a general nature
Effect of decreased gravity on circulation in the rat
It has been reported that hypokinesia and bed rest induce cardiovascular changes similar to those observed in space flights. Using an animal model that was developed in our laboratory and that was extensively studied and characterized in our laboratory and other laboratories in this country and abroad, we have studied circulatory mechanisms that occur during exposure to hypokinesia (with or without negative tilt) as well as during readaptation to control conditions (free activity). We believe that this study contributes to better understanding of mammalian circulatory mechanisms that operate under 1-g force and will serve to provide control data to be compared with cardiovascular data obtained in conditions of a Space lab. Because survey and anesthesia drastically decrease cardiac output and other circulatory parameters in rats, only unanesthetized rats were used in experiments. Aorta and right atrium of the animals were permanently cannulated fifteen to twenty days before experiments. Arterial and right ventricular blood pressures, cardiac output, cerebral and other regional blood flow, ECG, other cardiovascular parameters, and oxygen consumption were measured with techniques routinely used in our laboratory. Specifically, we undertook the following investigations during the period of three years: (1) A study of circulatory changes (right ventricular pressure, arterial blood pressure, heart rate, cardiac output) during exposure of rats to hypokinetic conditions. Used the head down tilted Holton-Musacchia system in order to compare the results with the results already obtained on unrestrained rats, (2) Humoral changes were investigated in animals exposed to hypokinesia; also, lymphocyte and neutrophil levels in hypokinetic animals (with or without tilt) were determined to ascertain the level of induced stress and possible changes observed in weightless animals, and (3) circulating blood volume was determined during and after hypokinesia
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