O Rubor de Corday e os Estudos da Irritabilidade e da Sensibilidade nos Séculos XVIII e XIX

Este artigo realiza uma breve retomada das ideias de alguns autores que discutiram se a sensibilidade e o pensamento persistiam nas cabeças decepadas dos condenados à guilhotina. Na controvérsia entre opiniões, os autores discutem a possibilidade de as partes do corpo, separadas do centro comum de sensibilidade, terem dor, ou se cabeça cortada permaneceria viva por alguns momentos após a decapitação, e se sofreria ou pensaria. Nessa retomada, discutiremos algumas questões relacionadas à irritabilidade, sensibilidade e unidade da consciência.Palavras-chave: Charlotte Corday. Guilhotina. Irritabilidade. Sensibilidade. Consciência. Corday's Flushing And The Studies Of Irritability And Sensitivity In The 18th And 19th CenturyABSTRACT This paper conducts a brief review of the ideas of some authors who discussed if sensibility and thought persisted in the severed heads of those condemned to the guillotine. In the controversy between opinions, the authors discuss the possibility that body parts, separated from the common center of sensibility, could have pain, or whether severed heads would remain alive for a few seconds after decapitation, and whether they would suffer or think. In this review, we will discuss some issues related to irritability, sensibility and the unity of consciousness.Keywords: Charlotte Corday. Guillotine. Irritability. Sensibility. Consciousness.

Why animals swirl and how they group

We report a possible solution for the long-standing problem of the biological function of swirling motion, when a group of animals orbits a common center of the group. We exploit the hypothesis that learning processes in the nervous system of animals may be modelled by reinforcement learning (RL) and apply it to explain the phenomenon. In contrast to hardly justified models of physical interactions between animals, we propose a small set of rules to be learned by the agents, which results in swirling. The rules are extremely simple and thus applicable to animals with very limited level of information processing. We demonstrate that swirling may be understood in terms of the escort behavior, when an individual animal tries to reside within a certain distance from the swarm center. Moreover, we reveal the biological function of swirling motion: a trained for swirling swarm is by orders of magnitude more resistant to external perturbations, than an untrained one. Using our approach we analyze another class of a coordinated motion of animals—a group locomotion in viscous fluid. On a model example we demonstrate that RL provides an optimal disposition of coherently moving animals with a minimal dissipation of energy.

Why Do Animals Swirl and How Do They Group?

We report a possible solution for the long-standing problem of the biological function of swirling motion, when a group of animals orbits a common center of the group. We exploit the hypothesis that learning processes in the nervous system of animals may be modelled by reinforcement learning (RL) and apply it to explain the phenomenon. In contrast to hardly justified models of physical interactions between animals, we propose a small set of rules to be learned by the agents, which results in swirling. The rules are extremely simple and thus applicable to animals with very limited level of information processing. We demonstrate that swirling may be understood in terms of the escort behavior, when an individual animal tries to reside within a certain distance from the swarm center. Moreover, we reveal the biological function of swirling motion: a trained for swirling swarm is by orders of magnitude more resistant to external perturbations, than an untrained one. Using our approach we analyze another class of a coordinated motion of animals – a group locomotion in viscous fluid. On a model example we demonstrate that RL provides an optimal disposition of coherently moving animals with a minimal dissipation of energy.

province

To Moscow! To Moscow! To Moscow!A. P. Chekhov, “Three Sisters”If you were destined to be born in the Empire,It’s best to find some province, by the ocean…I. Brodsky, “Letters to a Roman Friend”The relation between a province and a metropolis, like many other processes, is subject to periodic oscillations. Systole comes after diastole; creative energy tends to move towards the common center one day, and spreads among a number of local centers and objects another day. The trend seems to be changing right now. Some of today’s tendencies convey the suggestion that the centripetal motion is giving way to the centrifugal one. The metropolises’ attractiveness, which was so evident just a short time ago, is melting. It is starting to seem that life in small towns is healthier and safer and can satisfy a lot of cultural needs.Probably, one of the reasons is degradation of cultural policies of global and national centers. Metropolises “come down” with haughtiness and self-complacence and start to treat the provinces as cultural colonies (p. 18). In return, provinces ignore the models proposed by metropolises and pay more attention to their own identity (p. 27). Once again, the experience of national provincial architecture of the first half of the 20th century (pp. 32, 37) is reconsidered and reassessed. Protection of monuments of the local culture and history (p. 89), concern for industrial heritage, unique landscapes (p. 96) and unique appearances of small towns are gaining ground. We are living again in a time of change. How will the drastically changing world affect our attitude to provincial towns, their appearances and lifestyles, as well as the settlement system in general?

Clusters of Chemical Compounds as Polytopes of the Highest Dimension

General analytical expressions are obtained for calculating the dimension of multi-shell clusters with a common center of shells in those cases when there is a metal atom in the center of the shells and when it is not. The shells can be in the shape of any body of Plato. It has been established that the gamma-copper cluster has the form of a cross-polytope of high dimension. The forms of clusters with ligands of the core of which is a chain of metal atoms or a metal polyhedron are geometrically investigated. It is shown that if the skeleton is a chain of metal atoms, then the cluster is polytope composed of two polytopes of higher dimension adjacent to each other along a flat section containing a chain. If the skeleton is a metal polyhedron, then a cluster of higher dimension has several ligand shells.

Motion of the Infinitesimal Variable Mass in the Generalized Circular Restricted Three-Body Problem under the Effect of Asteroids Belt

The present paper deals with the study of the motion’s properties of the infinitesimal variable mass body moving in the same orbital plan as two massive bodies (considered as primaries). It is assumed that the massive bodies have radiating effects, have oblate shapes, and are moving in circular orbits around their common center of mass. Using the procedures established by Singh and Abouelmagd, we determined the equations of motion of the infinitesimal body for which we assumed that under the effects of radiation and oblateness of the primaries, its mass varies following Jean’s law. We evaluated analytically and numerically the locations of equilibrium points and examined the stability of these equilibrium points. Finally, we found that all the points are unstable.

Swirlonic state of active matter

We report a novel state of active matter—a swirlonic state. It is comprised of swirlons, formed by groups of active particles orbiting their common center of mass. These quasi-particles demonstrate a surprising behavior: In response to an external load they move with a constant velocity proportional to the applied force, just as objects in viscous media. The swirlons attract each other and coalesce forming a larger, joint swirlon. The coalescence is extremely slow, decelerating process, resulting in a rarified state of immobile quasi-particles. In addition to the swirlonic state, we observe gaseous, liquid and solid states, depending on the inter-particle and self-driving forces. Interestingly, in contrast to molecular systems, liquid and gaseous states of active matter do not coexist. We explain this unusual phenomenon by the lack of fast particles in active matter. We perform extensive numerical simulations and theoretical analysis. The predictions of the theory agree qualitatively and quantitatively with the simulation results.

Behavior of Small Variable Mass Particle in Electromagnetic Copenhagen Problem

The paper presents the behavior of the motion properties of the variable mass test particle (third body), moving under the influence of the two equal primaries having electromagnetic dipoles. These primaries move on the same circular path around their common center of mass in the same plane. We have determined the equations of motion of the test particle whose mass varies according to Jean's law. Using the system of equations of motion we have evaluated the locations of equilibrium points, their movements and basins of the attracting domain. Finally, we examine the stability of these equilibrium points, all of which are unstable.

An Alternative Method for Shaking Force Balancing of the 3RRR PPM through Acceleration Control of the Center of Mass

The problem of shaking force balancing of robotic manipulators, which allows the elimination or substantial reduction of the variable force transmitted to the fixed frame, has been traditionally solved by optimal mass redistribution of the moving links. The resulting configurations have been achieved by adding counterweights, by adding auxiliary structures or, by modifying the form of the links from the early design phase. This leads to an increase in the mass of the elements of the mechanism, which in turn leads to an increment of the torque transmitted to the base (the shaking moment) and of the driving torque. Thus, a balancing method that avoids the increment in mass is very desirable. In this article, the reduction of the shaking force of robotic manipulators is proposed by the optimal trajectory planning of the common center of mass of the system, which is carried out by “bang-bang” profile. This allows a considerable reduction in shaking forces without requiring counterweights, additional structures, or changes in form. The method, already presented in the literature, is resumed in this case using a direct and easy to automate modeling technique based on fully Cartesian coordinates. This permits to express the common center of mass, the shaking force, and the shaking moment of the manipulator as simple analytic expressions. The suggested modeling procedure and balancing technique are illustrated through the balancing of the 3RRR planar parallel manipulator (PPM). Results from computer simulations are reported.

Revolution of Charged Particles in a Central Field of Attraction with Emission of Radiation

A particle of mass nm, carrying the electronic charge -e, revolves in an orbit through angle ψ at distances nr from a center of force of attraction, with angular momenta nL perpendicular to the orbital plane, where n is an integer greater than 0, m the electronic mass and r1 is the radius of the first circular orbit. The equation of motion of the nth orbit of revolution is derived, revealing that an excited particle revolves in an unclosed elliptic orbit, with emission of radiation at the frequency of revolution, before settling down, after many cycles of ψ, in a stable circular orbit. In unipolar revolution, a radiating particle settles in a circular orbit of radius nr1 round a positively charged nucleus. In bipolar revolution, two radiating particles of the same mass nm and charges e and –e, settle in a circular stable orbit of radius ns1 round a common center of mass, where s1 is the radius of the first orbit. Discrete masses nm and angular momenta nL lead to quantization of the orbits outside Bohr’s quantum mechanics. The frequency of radiation in the bipolar revolution is found to be in conformity with the Balmer-Rydberg formula for the spectral lines of radiation from the atom hydrogen gas. There is a spread in frequency of emitted radiation, the frequency in the final circle being the highest, which might explain hydrogen fine structure, as observed with a diffraction grating of high resolution. The unipolar revolution is identified with the solid or liquid state of hydrogen and bipolar revolution with the gas state.