12,705 research outputs found
Transformation of anthropological status in elderly with type II diabetes through exercise: pilates and aerobic exercise
Las estadísticas muestran que 285 millones de personas sufren de Diabetes Tipo II, esto es el 6% de la población mundial adulta y 60 millones de personas en los Estados Unidos (10% de la población). De los 47 millones de habitantes que posee España, mas de 3 millones de personas sufren de diabetes (6.4%). En el año 2010 se gastaron más de 106 mil millones de dólares en salud por causa de la diabetes en los Estados Unidos. El ejercicio físico es una manera de evitar la diabetes en la población a través de: un mejor uso de la propia insulina producida por el cuerpo, de la quema de grasas, del control del peso corporal, del aumento de la fuerza muscular y del aumento en la densidad y calidad ósea. Una frecuencia semanal de 250 a 300 minutos de actividad física puede resultar de gran ayuda en el control de esta patología. La práctica de Pilates es un ejercicio que puede ser utilizado para lograr fácilmente un estado físico saludable. Puede ser realizado en el hogar, aprendiendo la técnica a través de la TV o de DVDs, es conveniente y sin costos. Además no presenta riesgos para las personas con diabetes tipo II, quienes son vulnerables por presentar una biomecánica disminuida en los miembros inferiores y/o una disfunción de la marcha
Fermionic entanglement ambiguity in non-inertial frames
We analyse an ambiguity in previous works on entanglement of fermionic fields
in non-inertial frames. This ambiguity, related to the anticommutation
properties of field operators, leads to non-unique results when computing
entanglement measures for the same state. We show that the ambiguity disappears
when we introduce detectors, which are in any case necessary as a means to
probe the field entanglement.Comment: 9 pages, 4 figures. Revtex 4.1, added Journal referenc
Triangle-Well and Ramp Interactions in One-Dimensional Fluids: A Fully Analytic Exact Solution
The exact statistical-mechanical solution for the equilibrium properties,
both thermodynamic and structural, of one-dimensional fluids of particles
interacting via the triangle-well and the ramp potentials is worked out. In
contrast to previous studies, where the radial distribution function was
obtained numerically from the structure factor by Fourier inversion, we provide
a fully analytic representation of up to any desired distance. The
solution is employed to perform an extensive study of the equation of state,
the excess internal energy per particle, the residual multiparticle entropy,
the structure factor, the radial distribution function, and the direct
correlation function. In addition, scatter plots of the bridge function versus
the indirect correlation function are used to gauge the reliability of the
hypernetted-chain, Percus--Yevick, and Martynov--Sarkisov closures. Finally,
the Fisher--Widom and Widom lines are obtained in the case of the triangle-well
model.Comment: 19 pages, 9 figure
A Chern-Simons Pandemic
In this paper we study the consistency of generalized global symmetries in
theories of quantum gravity, in particular string theory. Such global
symmetries arise in theories with -form gauge fields, and for spacetime
dimension there are obstructions to their breaking even by quantum
effects of charged objects. In 4d theories with a 2-form gauge field (or with
an axion scalar), these fields endow Schwarzschild black holes with quantum
hair, a global charge leading to usual trouble with remnants. We describe
precise mechanisms, and examples from string compactifications and holographic
pairs, in which these problems are evaded by either gauging or breaking the
global symmetry, via (suitable versions of) Stuckelberg or Kaloper-Sorbo
couplings. We argue that even in the absence of such couplings, the generic
solution in string theory is the breaking of the global symmetries by cubic
Chern-Simons terms involving different antisymmetric tensor fields. We
conjecture that any theory with (standard or higher-degree antisymmetric
tensor) gauge fields is in the Swampland unless its effective action includes
such Chern-Simons terms. This conjecture implies that many familiar theories,
like QED (even including the charged particles required by the Weak Gravity
Conjecture) or supergravity in four dimensions, are
inconsistent in quantum gravity unless they are completed by these Chern-Simons
terms.Comment: 60 pages, 2 figure
Steady self-diffusion in classical gases
A steady self-diffusion process in a gas of hard spheres at equilibrium is
analyzed. The system exhibits a constant gradient of labeled particles. Neither
the concentration of these particles nor its gradient are assumed to be small.
It is shown that the Boltzmann-Enskog kinetic equation has an exact solution
describing the state. The hydrodynamic transport equation for the density of
labeled particles is derived, with an explicit expression for the involved
self-diffusion transport coefficient. Also an approximated expression for the
one-particle distribution function is obtained. The system does not exhibit any
kind of rheological effects. The theoretical predictions are compared with
numerical simulations using the direct simulation Monte Carlo method and a
quite good agreement is found
Uniform self-diffusion in a granular gas
A granular gas composed of inelastic hard spheres or disks in the homogeneous
cooling state is considered. Some of the particles are labeled and their number
density exhibits a time-independent linear profile along a given direction. As
a consequence, there is a uniform flux of labeled particles in that direction.
It is shown that the inelastic Boltzmann-Enskog kinetic equation has a solution
describing this self-diffusion state. Approximate expressions for the transport
equation and the distribution function of labeled particles are derived. The
theoretical predictions are compared with simulation results obtained using the
direct Monte Carlo method to generate solutions of the kinetic equation. A
fairly good agreement is found
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