Discrete restricted four-body problem: Existence of proof of equilibria and reproducibility of periodic orbits

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Minesaki, Yukitaka [Tokushima Bunri University, Nishihama, Yamashiro-cho, Tokushima 770-8514 (Japan)

2015-01-01

We propose the discrete-time restricted four-body problem (d-R4BP), which approximates the orbits of the restricted four-body problem (R4BP). The d-R4BP is given as a special case of the discrete-time chain regularization of the general N-body problem published in Minesaki. Moreover, we analytically prove that the d-R4BP yields the correct orbits corresponding to the elliptic relative equilibrium solutions of the R4BP when the three primaries form an equilateral triangle at any time. Such orbits include the orbit of a relative equilibrium solution already discovered by Baltagiannis and Papadakis. Until the proof in this work, there has been no discrete analog that preserves the orbits of elliptic relative equilibrium solutions in the R4BP. For a long time interval, the d-R4BP can precisely compute some stable periodic orbits in the Sun–Jupiter–Trojan asteroid–spacecraft system that cannot necessarily be reproduced by other generic integrators.

On an efficient and accurate method to integrate restricted three-body orbits

Science.gov (United States)

Murison, Marc A.

1989-01-01

This work is a quantitative analysis of the advantages of the Bulirsch-Stoer (1966) method, demonstrating that this method is certainly worth considering when working with small N dynamical systems. The results, qualitatively suspected by many users, are quantitatively confirmed as follows: (1) the Bulirsch-Stoer extrapolation method is very fast and moderately accurate; (2) regularization of the equations of motion stabilizes the error behavior of the method and is, of course, essential during close approaches; and (3) when applicable, a manifold-correction algorithm reduces numerical errors to the limits of machine accuracy. In addition, for the specific case of the restricted three-body problem, even a small eccentricity for the orbit of the primaries drastically affects the accuracy of integrations, whether regularized or not; the circular restricted problem integrates much more accurately.

Poincaré and the three body problem

CERN Document Server

Barrow-Green, June

1997-01-01

The idea of chaos figures prominently in mathematics today. It arose in the work of one of the greatest mathematicians of the late 19th century, Henri Poincaré, on a problem in celestial mechanics: the three body problem. This ancient problem-to describe the paths of three bodies in mutual gravitational interaction-is one of those which is simple to pose but impossible to solve precisely. Poincaré's famous memoir on the three body problem arose from his entry in the competition celebrating the 60th birthday of King Oscar of Sweden and Norway. His essay won the prize and was set up in print as a paper in Acta Mathematica when it was found to contain a deep and critical error. In correcting this error Poincaré discovered mathematical chaos, as is now clear from Barrow-Green's pioneering study of a copy of the original memoir annotated by Poincaré himself, recently discovered in the Institut Mittag-Leffler in Stockholm. Poincaré and the Three Body Problem opens with a discussion of the development of the th...

The three-body problem from Pythagoras to Hawking

CERN Document Server

Valtonen, Mauri; Kholshevnikov, Konstantin; Mylläri, Aleksandr; Orlov, Victor; Tanikawa, Kiyotaka

2016-01-01

This book, written for a general readership, reviews and explains the three-body problem in historical context reaching to latest developments in computational physics and gravitation theory. The three-body problem is one of the oldest problems in science and it is most relevant even in today’s physics and astronomy. The long history of the problem from Pythagoras to Hawking parallels the evolution of ideas about our physical universe, with a particular emphasis on understanding gravity and how it operates between astronomical bodies. The oldest astronomical three-body problem is the question how and when the moon and the sun line up with the earth to produce eclipses. Once the universal gravitation was discovered by Newton, it became immediately a problem to understand why these three-bodies form a stable system, in spite of the pull exerted from one to the other. In fact, it was a big question whether this system is stable at all in the long run. Leading mathematicians attacked this problem over more than...

Lavine method applied to three body problems

International Nuclear Information System (INIS)

Mourre, Eric.

1975-09-01

The methods presently proposed for the three body problem in quantum mechanics, using the Faddeev approach for proving the asymptotic completeness, come up against the presence of new singularities when the potentials considered v(α)(x(α)) for two-particle interactions decay less rapidly than /x(α)/ -2 ; and also when trials are made for solving the problem with a representation space whose dimension for a particle is lower than three. A method is given that allows the mathematical approach to be extended to three body problem, in spite of singularities. Applications are given [fr

The three body problem with energy dependent potentials

International Nuclear Information System (INIS)

Kim, Y.E.; McKay, C.M.; McKellar, B.H.J.

1975-10-01

It is shown how to generalize the three body equations of Faddeev, and of Karlsson and Zeiger, to include the case when the two body potential is energy dependent. Such generalizations will prove useful in the three nucleon problem and in three body models of nuclear reactions. (author)

Pseudo-Newtonian planar circular restricted 3-body problem

International Nuclear Information System (INIS)

Dubeibe, F.L.; Lora-Clavijo, F.D.; González, Guillermo A.

2017-01-01

We study the dynamics of the planar circular restricted three-body problem in the context of a pseudo-Newtonian approximation. By using the Fodor–Hoenselaers–Perjés procedure, we perform an expansion in the mass potential of a static massive spherical source up to the first non-Newtonian term, giving place to a gravitational potential that includes first-order general relativistic effects. With this result, we model a system composed by two pseudo-Newtonian primaries describing circular orbits around their common center of mass, and a test particle orbiting the system in the equatorial plane. The dynamics of the new system of equations is studied in terms of the Poincaré section method and the Lyapunov exponents, where the introduction of a new parameter ϵ, allows us to observe the transition from the Newtonian to the pseudo-Newtonian regime. We show that when the Jacobian constant is fixed, a chaotic orbit in the Newtonian regime can be either chaotic or regular in the pseudo-Newtonian approach. As a general result, we find that most of the pseudo-Newtonian configurations are less stable than their Newtonian equivalent.

Pseudo-Newtonian planar circular restricted 3-body problem

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Dubeibe, F.L., E-mail: fldubeibem@unal.edu.co [Facultad de Ciencias Humanas y de la Educación, Universidad de los Llanos, Villavicencio (Colombia); Grupo de Investigación en Relatividad y Gravitación, Escuela de Física, Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia); Lora-Clavijo, F.D., E-mail: fadulora@uis.edu.co [Grupo de Investigación en Relatividad y Gravitación, Escuela de Física, Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia); González, Guillermo A., E-mail: guillermo.gonzalez@saber.uis.edu.co [Grupo de Investigación en Relatividad y Gravitación, Escuela de Física, Universidad Industrial de Santander, A.A. 678, Bucaramanga (Colombia)

2017-02-12

We study the dynamics of the planar circular restricted three-body problem in the context of a pseudo-Newtonian approximation. By using the Fodor–Hoenselaers–Perjés procedure, we perform an expansion in the mass potential of a static massive spherical source up to the first non-Newtonian term, giving place to a gravitational potential that includes first-order general relativistic effects. With this result, we model a system composed by two pseudo-Newtonian primaries describing circular orbits around their common center of mass, and a test particle orbiting the system in the equatorial plane. The dynamics of the new system of equations is studied in terms of the Poincaré section method and the Lyapunov exponents, where the introduction of a new parameter ϵ, allows us to observe the transition from the Newtonian to the pseudo-Newtonian regime. We show that when the Jacobian constant is fixed, a chaotic orbit in the Newtonian regime can be either chaotic or regular in the pseudo-Newtonian approach. As a general result, we find that most of the pseudo-Newtonian configurations are less stable than their Newtonian equivalent.

First order normalization in the perturbed restricted three–body ...

African Journals Online (AJOL)

This paper performs the first order normalization that will be employed in the study of the nonlinear stability of triangular points of the perturbed restricted three – body problem with variable mass. The problem is perturbed in the sense that small perturbations are given in the coriolis and centrifugal forces. It is with variable ...

Three-body problem in d-dimensional space: Ground state, (quasi)-exact-solvability

Science.gov (United States)

Turbiner, Alexander V.; Miller, Willard; Escobar-Ruiz, M. A.

2018-02-01

As a straightforward generalization and extension of our previous paper [A. V. Turbiner et al., "Three-body problem in 3D space: Ground state, (quasi)-exact-solvability," J. Phys. A: Math. Theor. 50, 215201 (2017)], we study the aspects of the quantum and classical dynamics of a 3-body system with equal masses, each body with d degrees of freedom, with interaction depending only on mutual (relative) distances. The study is restricted to solutions in the space of relative motion which are functions of mutual (relative) distances only. It is shown that the ground state (and some other states) in the quantum case and the planar trajectories (which are in the interaction plane) in the classical case are of this type. The quantum (and classical) Hamiltonian for which these states are eigenfunctions is derived. It corresponds to a three-dimensional quantum particle moving in a curved space with special d-dimension-independent metric in a certain d-dependent singular potential, while at d = 1, it elegantly degenerates to a two-dimensional particle moving in flat space. It admits a description in terms of pure geometrical characteristics of the interaction triangle which is defined by the three relative distances. The kinetic energy of the system is d-independent; it has a hidden sl(4, R) Lie (Poisson) algebra structure, alternatively, the hidden algebra h(3) typical for the H3 Calogero model as in the d = 3 case. We find an exactly solvable three-body S3-permutationally invariant, generalized harmonic oscillator-type potential as well as a quasi-exactly solvable three-body sextic polynomial type potential with singular terms. For both models, an extra first order integral exists. For d = 1, the whole family of 3-body (two-dimensional) Calogero-Moser-Sutherland systems as well as the Tremblay-Turbiner-Winternitz model is reproduced. It is shown that a straightforward generalization of the 3-body (rational) Calogero model to d > 1 leads to two primitive quasi

Robe's Restricted Problem of 2 + 2 Bodies with a Roche Ellipsoid - Triaxial System

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Aggarwal, Rajiv; Kaur, Bhavneet; Yadav, Sushil

2018-03-01

This paper investigates the motion of two infinitesimal masses on the location and stability of the equilibrium points in Robe's restricted problem of 2 + 2 bodies with the bigger primary a Roche ellipsoid and the smaller a triaxial body. We suppose the bigger primary of mass m 1 to be filled with a homogeneous incompressible fluid of density ρ 1. The third and the fourth bodies (of mass m 3 and m 4 respectively) are small solid spheres of density ρ 3 and ρ 4 respectively inside the ellipsoid, with the assumption that the mass and the radius of the third and the fourth body are infinitesimal. We assume that m 2 is describing a circle around m 1. The masses m 3 and m 4 mutually attract each other, do not influence the motion of m 1 and m 2 but are influenced by them. We have taken into consideration all the three components of the pressure field in deriving the expression for the buoyancy force viz (i) due to the own gravitational field of the fluid (ii) that originating in the attraction of m 2 (iii) that arising from the centrifugal force. In this paper, equilibrium solutions of m 3 and m 4 and their linear stability are analyzed.

Spectral sum rules for the three-body problem

International Nuclear Information System (INIS)

Bolle, D.; Osborn, T.A.

1982-01-01

This paper derives a number of sum rules for nonrelativistic three-body scattering. These rules are valid for any finite region μ in the six-dimensional coordinate space. They relate energy moments of the trace of the onshell time-delay operator to the energy-weighted probability for finding the three-body bound-state wave functions in the region μ. If μ is all of the six-dimensional space, the global form of the sum rules is obtained. In this form the rules constitute higher-order Levinson's theorems for the three-body problem. Finally, the sum rules are extended to allow the energy momtns have complex powers

Continuum capture in the three-body problem

International Nuclear Information System (INIS)

Sellin, I.A.

1980-01-01

The three-body problem, especially the problem of electron capture to the continuum in heavy particle collisions is reviewed. Major topics covered include: second born-induced asymmetry in electron capture to the continuum; historical context, links to other tests of atomic scattering theory; experiments characterizing the velocity distribution of ECC electrons; other atomic physics tests of high velocity Born expansions; atom capture; capture by positrons; and pion capture to the continuum

Topics in three body problems

International Nuclear Information System (INIS)

Amado, R.D.

1975-01-01

An overview of the formal theory of the three-body problem as it has developed in the past twelve years is given. The formal structure of the theory, some of the techniques that have developed for handling the theory, and some results on how general quantum mechanical principles structure the results, are presented. The discussion is held entirely in the context of non-relativistic quantum mechanics with short-range forces. In this presentation the main outline of the theory is stressed, often at the expense of mathematical rigour [pt

Nuclear three-body problem and energy-dependent potentials

International Nuclear Information System (INIS)

Abdurakhmanov, A.; Akhmadkhodzhaev, B.; Zubarev, A.L.; Irgaziev, B.F.

1985-01-01

Energy-dependent potentials in the three-body problem are being considered. Three-particle equations for the case of pairing energy-dependent potentials are generalized and the problems related to this ambiguous generalization are investigated. In terms of the equations obtained the tritium binding energy and vertex coupling constants (Tdn) and (Tdν) are evaluated. The binding energy and, especially, coupling constants are shown to be sensitive to a shape of the energy-dependent potential

Effect of Perturbations in Coriolis and Centrifugal Forces on the Nonlinear Stability of Equilibrium Point in Robe's Restricted Circular Three-Body Problem

Directory of Open Access Journals (Sweden)

P. P. Hallan

2008-01-01

Full Text Available The effect of perturbations in Coriolis and cetrifugal forces on the nonlinear stability of the equilibrium point of the Robe's (1977 restricted circular three-body problem has been studied when the density parameter K is zero. By applying Kolmogorov-Arnold-Moser (KAM theory, it has been found that the equilibrium point is stable for all mass ratios μ in the range of linear stability 8/9+(2/3((43/25ϵ1−(10/3ϵ<μ<1, where ϵ and ϵ1 are, respectively, the perturbations in Coriolis and centrifugal forces, except for five mass ratios μ1=0.93711086−1.12983217ϵ+1.50202694ϵ1, μ2 = 0.9672922−0.5542091ϵ+ 1.2443968ϵ1, μ3=0.9459503−0.70458206ϵ+ 1.28436549ϵ1, μ4=0.9660792−0.30152273ϵ + 1.11684064ϵ1, μ5=0.893981−2.37971679ϵ + 1.22385421ϵ1, where the theory is not applicable.

On the photo-gravitational restricted four-body problem with variable mass

Science.gov (United States)

Mittal, Amit; Agarwal, Rajiv; Suraj, Md Sanam; Arora, Monika

2018-05-01

This paper deals with the photo-gravitational restricted four-body problem (PR4BP) with variable mass. Following the procedure given by Gascheau (C. R. 16:393-394, 1843) and Routh (Proc. Lond. Math. Soc. 6:86-97, 1875), the conditions of linear stability of Lagrange triangle solution in the PR4BP are determined. The three radiating primaries having masses m1, m2 and m3 in an equilateral triangle with m2=m3 will be stable as long as they satisfy the linear stability condition of the Lagrangian triangle solution. We have derived the equations of motion of the mentioned problem and observed that there exist eight libration points for a fixed value of parameters γ (m at time t/m at initial time, 0Cambridge University Press, Cambridge, 1928), 0≤α≤2.2), the mass parameter μ=0.005 and radiation parameters qi, (0< qi≤1, i=1, 2, 3). All the libration points are non-collinear if q2≠ q3. It has been observed that the collinear and out-of-plane libration points also exist for q2=q3. In all the cases, each libration point is found to be unstable. Further, zero velocity curves (ZVCs) and Newton-Raphson basins of attraction are also discussed.

Non-integrability of the Anisotropic Stormer Problem and the Isosceles Three-Body Problem

Science.gov (United States)

Nomikos, D. G.; Papageorgiou, V. G.

2009-02-01

We study the Anisotropic Stormer Problem (ASP) and the Isosceles Three-Body Problem (IP), from the viewpoint of integrability, using Morales-Ramis theory and its generalization. The study of their integrability presents particular interest since they model important physical phenomena. Both problems can be reduced with respect to the S1 symmetry. Almeida and Stuchi [M.A. Almeida, T.J. Stuchi, Non-integrability of the anisotropic Stormer problem with angular momentum, Physica D 189 (2004) 219-233] proved that the reduced ASP is non-integrable for almost all values of the parameters. In this paper we establish the non-integrability (in the extended Liouville sense) of the remaining cases. The IP is a special case of the three-body problem and it can be considered as a generalization of the Sitnikov problem. Here we prove that the complexified reduced IP does not admit an additional independent meromorphic first integral.

A cluster expansion for bound three-alpha particles as a three-body problem

International Nuclear Information System (INIS)

Osman, A.

1981-08-01

A three-body model is proposed to study the nuclear bound states. The nucleus is described as a bound state of three clusters. A cluster expansion is introduced for the three cluster bound state problem. The present integral equations are treated by simple approximate solutions, which lead to effective potentials by using the present cluster expansion. The 12 C nucleus is described as a three-alpha particle bound state. The binding energy of 12 C is calculated numerically using the present cluster expansion as bound three-alpha clusters. The present three-body cluster expansion calculations are very near to the exact three-body calculations using separable potentials. The present theoretical calculations are in good agreement with the experimental measurements. (author)

LAGRANGE SOLUTIONS TO THE DISCRETE-TIME GENERAL THREE-BODY PROBLEM

International Nuclear Information System (INIS)

Minesaki, Yukitaka

2013-01-01

There is no known integrator that yields exact orbits for the general three-body problem (G3BP). It is difficult to verify whether a numerical procedure yields the correct solutions to the G3BP because doing so requires knowledge of all 11 conserved quantities, whereas only six are known. Without tracking all of the conserved quantities, it is possible to show that the discrete general three-body problem (d-G3BP) yields the correct orbits corresponding to Lagrange solutions of the G3BP. We show that the d-G3BP yields the correct solutions to the G3BP for two special cases: the equilateral triangle and collinear configurations. For the triangular solution, we use the fact that the solution to the three-body case is a superposition of the solutions to the three two-body cases, and we show that the three bodies maintain the same relative distances at all times. To obtain the collinear solution, we assume a specific permutation of the three bodies arranged along a straight rotating line, and we show that the d-G3BP maintains the same distance ratio between two bodies as in the G3BP. Proving that the d-G3BP solutions for these cases are equivalent to those of the G3BP makes it likely that the d-G3BP and G3BP solutions are equivalent in other cases. To our knowledge, this is the first work that proves the equivalence of the discrete solutions and the Lagrange orbits.

Solar sail trajectory design in the Earth-Moon circular restricted three body problem

Science.gov (United States)

Das, Ashwati

The quest to explore the Moon has helped resolve scientific questions, has spurred leaps in technology development, and has revealed Earth's celestial companion to be a gateway to other destinations. With a renewed focus on returning to the Moon in this decade, alternatives to chemical propulsion systems are becoming attractive methods to efficiently use scarce resources and support extended mission durations. Thus, an investigation is conducted to develop a general framework, that facilitates propellant-free Earth-Moon transfers by exploiting sail dynamics in combination with advantageous transfer options offered in the Earth-Moon circular restricted multi-body dynamical model. Both periodic orbits in the vicinity of the Earth-Moon libration points, and lunar-centric long-term capture orbits are incorporated as target destinations to demonstrate the applicability of the general framework to varied design scanarios, each incorporating a variety of complexities and challenges. The transfers are comprised of three phases - a spiral Earth escape, a transit period, and, finally, the capture into a desirable orbit in the vicinity of the Moon. The Earth-escape phase consists of spiral trajectories constructed using three different sail steering strategies - locally optimal, on/off and velocity tangent. In the case of the Earth-libration point transfers, naturally occurring flow structures (e.g., invariant manifolds) arising from the mutual gravitational interaction of the Earth and Moon are exploited to link an Earth departure spiral with a destination orbit. In contrast, sail steering alone is employed to establish a link between the Earth-escape phase and capture orbits about the Moon due to a lack of applicable natural structures for the required connection. Metrics associated with the transfers including flight-time and the influence of operational constraints, such as occultation events, are investigated to determine the available capabilities for Earth

The three-body problem and equivariant Riemannian geometry

Science.gov (United States)

Alvarez-Ramírez, M.; García, A.; Meléndez, J.; Reyes-Victoria, J. G.

2017-08-01

We study the planar three-body problem with 1/r2 potential using the Jacobi-Maupertuis metric, making appropriate reductions by Riemannian submersions. We give a different proof of the Gaussian curvature's sign and the completeness of the space reported by Montgomery [Ergodic Theory Dyn. Syst. 25, 921-947 (2005)]. Moreover, we characterize the geodesics contained in great circles.

Properties of three-body decay functions derived with time-like jet calculus beyond leading order

International Nuclear Information System (INIS)

Sugiura, Tetsuya

2002-01-01

Three-body decay functions in time-like parton branching are calculated using the jet calculus to the next-to-leading logarithmic (NLL) order in perturbative quantum chromodynamics (QCD). The phase space contributions from each of the ladder diagrams and interference diagrams are presented. We correct part of the results for the three-body decay functions calculated previously by two groups. Employing our new results, the properties of the three-body decay functions in the regions of soft partons are examined numerically. Furthermore, we examine the contribution of the three-body decay functions modified by the restriction resulting from the kinematical boundary of the phase space for two-body decay in the parton shower model. This restriction leads to some problems for the parton shower model. For this reason, we propose a new restriction introduced by the kinematical boundary of the phase space for two-body decay. (author)

Three-body dynamics in one dimension: a test model for the three-nucleon system with irreducible pionic diagrams

International Nuclear Information System (INIS)

Melde, T.; Canton, L.; Svenne, J.P.

2002-01-01

We formulate the three-body problem in one dimension in terms of the (Faddeev-type) integral equation approach. As an application, we develop a spinless, one-dimensional (1-D) model that mimics three-nucleon dynamics in one dimension. Using simple two-body potentials that reproduce the deuteron binding, we obtain that the three-body system binds at about 7.5 MeV. We then consider two types of residual pionic corrections in the dynamical equation; one related to the 2π-exchange three-body diagram, the other to the 1π-exchange three-body diagram. We find that the first contribution can produce an additional binding effect of about 0.9 MeV. The second term produces smaller binding effects, which are, however, dependent on the uncertainty in the off-shell extrapolation of the two-body t-matrix. This presents interesting analogies with what occurs in three dimensions. The paper also discusses the general three-particle quantum scattering problem, for motion restricted to the fall line. (author)

Hyperspherical Coulomb spheroidal basis in the Coulomb three-body problem

International Nuclear Information System (INIS)

Abramov, D. I.

2013-01-01

A hyperspherical Coulomb spheroidal (HSCS) representation is proposed for the Coulomb three-body problem. This is a new expansion in the set of well-known Coulomb spheroidal functions. The orthogonality of Coulomb spheroidal functions on a constant-hyperradius surface ρ = const rather than on a constant-internuclear-distance surface R = const, as in the traditional Born-Oppenheimer approach, is a distinguishing feature of the proposed approach. Owing to this, the HSCS representation proves to be consistent with the asymptotic conditions for the scattering problem at energies below the threshold for three-body breakup: only a finite number of radial functions do not vanish in the limit of ρ→∞, with the result that the formulation of the scattering problem becomes substantially simpler. In the proposed approach, the HSCS basis functions are considerably simpler than those in the well-known adiabatic hyperspherical representation, which is also consistent with the asymptotic conditions. Specifically, the HSCS basis functions are completely factorized. Therefore, there arise no problems associated with avoided crossings of adiabatic hyperspherical terms.

Precise numerical results for limit cycles in the quantum three-body problem

International Nuclear Information System (INIS)

Mohr, R.F.; Furnstahl, R.J.; Hammer, H.-W.; Perry, R.J.; Wilson, K.G.

2006-01-01

The study of the three-body problem with short-range attractive two-body forces has a rich history going back to the 1930s. Recent applications of effective field theory methods to atomic and nuclear physics have produced a much improved understanding of this problem, and we elucidate some of the issues using renormalization group ideas applied to precise nonperturbative calculations. These calculations provide 11-12 digits of precision for the binding energies in the infinite cutoff limit. The method starts with this limit as an approximation to an effective theory and allows cutoff dependence to be systematically computed as an expansion in powers of inverse cutoffs and logarithms of the cutoff. Renormalization of three-body bound states requires a short range three-body interaction, with a coupling that is governed by a precisely mapped limit cycle of the renormalization group. Additional three-body irrelevant interactions must be determined to control subleading dependence on the cutoff and this control is essential for an effective field theory since the continuum limit is not likely to match physical systems (e.g., few-nucleon bound and scattering states at low energy). Leading order calculations precise to 11-12 digits allow clear identification of subleading corrections, but these corrections have not been computed

Existence of Resonance Stability of Triangular Equilibrium Points in Circular Case of the Planar Elliptical Restricted Three-Body Problem under the Oblate and Radiating Primaries around the Binary System

Directory of Open Access Journals (Sweden)

A. Narayan

2014-01-01

Full Text Available This paper analyzes the existence of resonance stability of the triangular equilibrium points of the planar elliptical restricted three-body problem when both the primaries are oblate spheroid as well as the source of radiation under the particular case, when e=0. We have derived Hamiltonian function describing the motion of infinitesimal mass in the neighborhood of the triangular equilibrium solutions taken as a convergent series. Hamiltonian function for the system has been derived and also expanded in powers of the generalized components of momenta. We have used canonical transformation to make the Hamiltonian function independent of true anomaly. The most interesting and distinguishable results of this study are establishing the relation for determining the range of stability at and near the resonance ω2=1/2 around the binary system.

Three-body scattering problem in the fixed center approximation: The case of attraction

Energy Technology Data Exchange (ETDEWEB)

Kudryavtsev, Alexander E. [National Research Center Kurchatov Institute, Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Gani, Vakhid A. [National Research Center Kurchatov Institute, Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Romanov, Alexander I. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

2016-12-15

We study the scattering of a light particle on a bound pair of heavy particles (e.g., the deuteron) within the fixed center approximation in the case of light-heavy attraction, solving the integral equation for the three-body Green's function both in the coordinate and in the momentum space. The results for the three-body scattering amplitude appear to be ambiguous -they depend on a single real parameter. This parameter may be fixed by a three-body input, e.g., the three-body scattering length. We also solve the integral equation for the three-body Green function in the momentum space, introducing a finite cut-off. We show that all three approaches are equivalent. We also discuss how our approach to the problem matches with the introduction of three-body contact interaction as done by other authors. (orig.)

The three-body problem in quantum mechanics

International Nuclear Information System (INIS)

Antunes, A.C.B.

1973-01-01

Different methods used in the analysis of the scattering of an elementary particle by a system of two bound particles are compared. All particles are considered spinless and distinguishable from each other. Two approaches are used in the treatment of the problem. In the first method we build an effective - potential which accounts for the interaction of the incident particle with the bound system. The second approach consists in treating the target as a system of two particles, whose momentum distribution is given by the bound state wavefunction. The three body system is then treated by the techniques of the multiple scattering series and of Glauber theory. (author)

Realizing all reduced syzygy sequences in the planar three-body problem

International Nuclear Information System (INIS)

Moeckel, Richard; Montgomery, Richard

2015-01-01

The configuration space of the planar three-body problem, reduced by rotations and with collisions excluded, has a rich topology which supports a large set of free homotopy classes. These classes have a simple description in terms of syzygy (or eclipse) sequences. Each homotopy class corresponds to a unique ‘reduced’ syzygy sequence. We prove that each reduced syzygy sequence is realized by a periodic solution of the rotation-reduced Newtonian planar three-body problem. The realizing solutions have small, nonzero angular momentum, repeatedly come very close to triple collision, and have lots of ‘stutters’—repeated syzygies of the same type, which cancel out up to homotopy. The heart of the proof stems from the work by one of us on symbolic dynamics arising out of the central configurations after the triple collision is blown up using McGehee's method. We end with a list of open problems. (paper)

Coulomb effects in deuteron stripping reactions as a three-body problem

International Nuclear Information System (INIS)

Osman, A.

1981-08-01

Deuteron stripping nuclear reactions are reconsidered as a three-body problem. The Coulomb effects between the proton and the target nucleus are investigated. The mathematical formalism introduces three-body integral equations which can be exactly calculated for such simple models. These coupled integral equations suitably include the Coulomb effects due to replusive or attractive Coulomb potential. Numerical calculations of the differential cross-sections of the reactions 28 Si(d,p) 29 Si and 40 Ca(d,p) 41 Ca are carried out showing the importance of the Coulomb effects. The angular distributions of these reactions are theoretically calculated and fitted to the experimental data. From this fitting, reasonable spectroscopic factors are obtained. Inclusion of Coulomb force in the three-body model are found to improve the results by a percentage of about 6.826%. (author)

Modified Strum functions method in the nuclear three body problem

International Nuclear Information System (INIS)

Nasyrov, M.; Abdurakhmanov, A.; Yunusova, M.

1997-01-01

Fadeev-Hahn equations in the nuclear three-body problem were solved by modified Sturm functions method. Numerical calculations were carried out the square well potential. It was shown that the convergence of the method is high and the binding energy value is in agreement with experimental one (A.A.D.)

Lagrangian relative equilibria for a gyrostat in the three-body problem: bifurcations and stability

Energy Technology Data Exchange (ETDEWEB)

Guirao, Juan L G; Vera, Juan A, E-mail: juan.garcia@upct.e, E-mail: juanantonio.vera@upct.e [Departamento de Matematica Aplicada y EstadIstica, Universidad Politecnica de Cartagena, Hospital de Marina, 30203 Cartagena, Region de Murcia (Spain)

2010-05-14

In this paper we consider the non-canonical Hamiltonian dynamics of a gyrostat in the frame of the three-body problem. Using geometric/mechanic methods we study the approximate dynamics of the truncated Legendre series representation of the potential of an arbitrary order. Working in the reduced problem, we study the existence of relative equilibria that we refer to as Lagrange type following the analogy with the standard techniques. We provide necessary and sufficient conditions for the linear stability of Lagrangian relative equilibria if the gyrostat morphology form is close to a sphere. Thus, we generalize the classical results on equilibria of the three-body problem and many results on them obtained by the classic approach for the case of rigid bodies.

CTBC. A program to solve the collinear three-body Coulomb problem. Bound states and scattering below the three-body disintegration threshold

International Nuclear Information System (INIS)

Tolstikhin, Oleg I.; Namba, Chusei

2003-08-01

A program to solve the quantum-mechanical collinear three-body Coulomb problem is described and illustrated by calculations for a number of representative systems and processes. In the internal region, the Schroedinger equation is solved in hyperspherical coordinates using the slow/smooth variable discretization method. In asymptotic regions, the solution is obtained in Jacobi coordinates using the asymptotic package GAILIT from the CPC library. Only bound states and scattering processes below the three-body disintegration threshold are considered here; resonances and fragmentation processes will be discussed in subsequent parts of this series. (author)

Solution of the Chandler-Gibson equations for a three-body test problem

International Nuclear Information System (INIS)

Gibson, A.G.; Waters, A.J.; Berthold, G.H.; Chandler, C.

1991-01-01

The Chandler-Gibson (CG) N-body equations are tested by considering the problem of three nonrelativistic particles moving on a line and interacting through attractive delta-function potentials. In particular, the input Born and overlap matrix-valued functions are evaluated analytically, and the CG equations are solved using a B-spline collocation method. The computed scattering matrix elements are within 0.5% of the known exact solutions, and the corresponding scattering probabilities are within 0.001% of the exact probabilities, both below and above the 3-body breakup threshold. These results establish that the CG method is practical, as well as theoretically correct, and may be a valuable approach for solving certain more complicated N-body scattering problems

Free time minimizers for the three-body problem

Science.gov (United States)

Moeckel, Richard; Montgomery, Richard; Sánchez Morgado, Héctor

2018-03-01

Free time minimizers of the action (called "semi-static" solutions by Mañe in International congress on dynamical systems in Montevideo (a tribute to Ricardo Mañé), vol 362, pp 120-131, 1996) play a central role in the theory of weak KAM solutions to the Hamilton-Jacobi equation (Fathi in Weak KAM Theorem in Lagrangian Dynamics Preliminary Version Number 10, 2017). We prove that any solution to Newton's three-body problem which is asymptotic to Lagrange's parabolic homothetic solution is eventually a free time minimizer. Conversely, we prove that every free time minimizer tends to Lagrange's solution, provided the mass ratios lie in a certain large open set of mass ratios. We were inspired by the work of Da Luz and Maderna (Math Proc Camb Philos Soc 156:209-227, 1980) which showed that every free time minimizer for the N-body problem is parabolic and therefore must be asymptotic to the set of central configurations. We exclude being asymptotic to Euler's central configurations by a second variation argument. Central configurations correspond to rest points for the McGehee blown-up dynamics. The large open set of mass ratios are those for which the linearized dynamics at each Euler rest point has a complex eigenvalue.

EJECTION AND CAPTURE DYNAMICS IN RESTRICTED THREE-BODY ENCOUNTERS

International Nuclear Information System (INIS)

Kobayashi, Shiho; Hainick, Yanir; Sari, Re'em; Rossi, Elena M.

2012-01-01

We study the tidal disruption of binaries by a massive point mass (e.g., the black hole at the Galactic center), and we discuss how the ejection and capture preference between unequal-mass binary members depends on which orbit they approach the massive object. We show that the restricted three-body approximation provides a simple and clear description of the dynamics. The orbit of a binary with mass m around a massive object M should be almost parabolic with an eccentricity of |1 – e| ∼ 1/3 1/3 times the binary rotation velocity, it would be abruptly disrupted, and the energy change at the encounter can be evaluated in a simple disruption model. We evaluate the probability distributions for the ejection and capture of circular binary members and for the final energies. In principle, for any hyperbolic (elliptic) orbit, the heavier member has more chance to be ejected (captured), because it carries a larger fraction of the orbital energy. However, if the orbital energy is close to zero, the difference between the two members becomes small, and there is practically no ejection and capture preferences. The preference becomes significant when the orbital energy is comparable to the typical energy change at the encounter. We discuss its implications to hypervelocity stars and irregular satellites around giant planets.

Muonic molecules as three-body Coulomb problem in adiabatic approximation

International Nuclear Information System (INIS)

Decker, M.

1994-04-01

The three-body Coulomb problem is treated within the framework of the hyperspherical adiabatic approach. The surface functions are expanded into Faddeev-type components in order to ensure the equivalent representation of all possible two-body contributions. It is shown that this decomposition reduces the numerical effort considerably. The remaining radial equations are solved both in the extreme and the uncoupled adiabatic approximation to determine the binding energies of the systems (dtμ) and (d 3 Heμ). Whereas the ground state is described very well in the uncoupled adiabatic approximation, the excited states should be treated within the coupled adiabatic approximation to obtain good agreement with variational calculations. (orig.)

Three-dimensional imaging of atomic four-body processes

CERN Document Server

Schulz, M; Fischer, D; Kollmus, H; Madison, D H; Jones, S; Ullrich, J

2003-01-01

To understand the physical processes that occur in nature we need to obtain a solid concept about the 'fundamental' forces acting between pairs of elementary particles. it is also necessary to describe the temporal and spatial evolution of many mutually interacting particles under the influence of these forces. This latter step, known as the few-body problem, remains an important unsolved problem in physics. Experiments involving atomic collisions represent a useful testing ground for studying the few-body problem. For the single ionization of a helium atom by charged particle impact, kinematically complete experiments have been performed since 1969. The theoretical analysis of such experiments was thought to yield a complete picture of the basic features of the collision process, at least for large collision energies. These conclusions are, however, almost exclusively based on studies of restricted electron-emission geometries. We report three- dimensional images of the complete electron emission pattern for...

Three-body problem in the ground-state representation

International Nuclear Information System (INIS)

Gonzalez, A.

1993-01-01

The ground-state probability density of a three-body system is used to construct a classical potential U whose minimum coincides exactly with the ground-state energy. The spectrum of excited states may approximately be obtained by imposing quasiclassical quantization conditions over the classical motion in U. We show nontrivial one-dimensional models in which either this quantization condition is exact or considerably improves the usual semiclassical quantization. For three-dimensional problems, the small-oscillation frequencies in states with total angular momentum L = 0 are computed. These frequencies could represent an improvement over the frequencies of triatomic molecules computed with the use of ordinary quasiclassics for the motion of the nuclei in the molecular term. By providing a semiclassical description of the first excited quantum states, the sketched approach rises some interesting questions such as, for example, the relevance (once again) of classical chaos to quantum mechanics

Three-body problem in quantum mechanics: Hyperspherical elliptic coordinates and harmonic basis sets

International Nuclear Information System (INIS)

Aquilanti, Vincenzo; Tonzani, Stefano

2004-01-01

Elliptic coordinates within the hyperspherical formalism for three-body problems were proposed some time ago [V. Aquilanti, S. Cavalli, and G. Grossi, J. Chem. Phys. 85, 1362 (1986)] and recently have also found application, for example, in chemical reaction theory [see O. I. Tolstikhin and H. Nakamura, J. Chem. Phys. 108, 8899 (1998)]. Here we consider their role in providing a smooth transition between the known 'symmetric' and 'asymmetric' parametrizations, and focus on the corresponding hyperspherical harmonics. These harmonics, which will be called hyperspherical elliptic, involve products of two associated Lame polynomials. We will provide an expansion of these new sets in a finite series of standard hyperspherical harmonics, producing a powerful tool for future applications in the field of scattering and bound-state quantum-mechanical three-body problems

A method for solving a three-body problem with energy-dependent interactions

International Nuclear Information System (INIS)

Safronov, A.N.

1994-01-01

A method is proposed for solving a three-body problem with energy-dependent interactions. This method is based on introducing the dependence of scattering operators and state vectors on an additional external parameter. Effects caused by the energy dependence of the interaction operator are investigated by using the unitary condition for the amplitude of the 2 → 2 and 2 → 3 transitions. It is shown, in particular, that taking this dependence into account leads to a change in the relation between the asymptotic normalization factor of the wave function of the three-body bound state and the vertex constant of virtual dissociation (synthesis) of the system into two fragments. 15 refs

Solving the three-body Coulomb breakup problem using exterior complex scaling

Energy Technology Data Exchange (ETDEWEB)

McCurdy, C.W.; Baertschy, M.; Rescigno, T.N.

2004-05-17

Electron-impact ionization of the hydrogen atom is the prototypical three-body Coulomb breakup problem in quantum mechanics. The combination of subtle correlation effects and the difficult boundary conditions required to describe two electrons in the continuum have made this one of the outstanding challenges of atomic physics. A complete solution of this problem in the form of a ''reduction to computation'' of all aspects of the physics is given by the application of exterior complex scaling, a modern variant of the mathematical tool of analytic continuation of the electronic coordinates into the complex plane that was used historically to establish the formal analytic properties of the scattering matrix. This review first discusses the essential difficulties of the three-body Coulomb breakup problem in quantum mechanics. It then describes the formal basis of exterior complex scaling of electronic coordinates as well as the details of its numerical implementation using a variety of methods including finite difference, finite elements, discrete variable representations, and B-splines. Given these numerical implementations of exterior complex scaling, the scattering wave function can be generated with arbitrary accuracy on any finite volume in the space of electronic coordinates, but there remains the fundamental problem of extracting the breakup amplitudes from it. Methods are described for evaluating these amplitudes. The question of the volume-dependent overall phase that appears in the formal theory of ionization is resolved. A summary is presented of accurate results that have been obtained for the case of electron-impact ionization of hydrogen as well as a discussion of applications to the double photoionization of helium.

A simple coordinate space approach to three-body problems ...

Indian Academy of Sciences (India)

We show how to treat the dynamics of an asymmetric three-body system consisting of one heavy and two identical light particles in a simple coordinate space variational approach. The method is constructive and gives an efficient way of resolving a three-body system to an effective two-body system. It is illustrated by ...

The Hill's three-body problem: a new deduction of motion equations

International Nuclear Information System (INIS)

Fuente Marcos, C. de la.

1995-01-01

Although the Hill's problem has been considered traditionally as a particular case of the restricted problem, it is not but rather a different problem with the same degree of generality. In this paper it is presented a new derivation of the motion equations obtained originally by Hill in 1878 as well as a brief discussion about its possible applications. (Author) 13 refs

Introduction to Hamiltonian dynamical systems and the N-body problem

CERN Document Server

Meyer, Kenneth R

2017-01-01

This third edition text provides expanded material on the restricted three body problem and celestial mechanics. With each chapter containing new content, readers are provided with new material on reduction, orbifolds, and the regularization of the Kepler problem, all of which are provided with applications. The previous editions grew out of graduate level courses in mathematics, engineering, and physics given at several different universities. The courses took students who had some background in differential equations and lead them through a systematic grounding in the theory of Hamiltonian mechanics from a dynamical systems point of view. This text provides a mathematical structure of celestial mechanics ideal for beginners, and will be useful to graduate students and researchers alike. Reviews of the second edition: "The primary subject here is the basic theory of Hamiltonian differential equations studied from the perspective of differential dynamical systems. The N-body problem is used as the primary exa...

Approximate Coulomb effects in the three-body scattering problem

International Nuclear Information System (INIS)

Haftel, M.I.; Zankel, H.

1981-01-01

From the momentum space Faddeev equations we derive approximate expressions which describe the Coulomb-nuclear interference in the three-body elastic scattering, rearrangement, and breakup problems and apply the formalism to p-d elastic scattering. The approximations treat the Coulomb interference as mainly a two-body effect, but we allow for the charge distribution of the deuteron in the p-d calculations. Real and imaginary parts of the Coulomb correction to the elastic scattering phase shifts are described in terms of on-shell quantities only. In the case of pure Coulomb breakup we recover the distorted-wave Born approximation result. Comparing the derived approximation with the full Faddeev p-d elastic scattering calculation, which includes the Coulomb force, we obtain good qualitative agreement in S and P waves, but disagreement in repulsive higher partial waves. The on-shell approximation investigated is found to be superior to other current approximations. The calculated differential cross sections at 10 MeV raise the question of whether there is a significant Coulomb-nuclear interference at backward angles

A restricted Steiner tree problem is solved by Geometric Method II

Science.gov (United States)

Lin, Dazhi; Zhang, Youlin; Lu, Xiaoxu

2013-03-01

The minimum Steiner tree problem has wide application background, such as transportation system, communication network, pipeline design and VISL, etc. It is unfortunately that the computational complexity of the problem is NP-hard. People are common to find some special problems to consider. In this paper, we first put forward a restricted Steiner tree problem, which the fixed vertices are in the same side of one line L and we find a vertex on L such the length of the tree is minimal. By the definition and the complexity of the Steiner tree problem, we know that the complexity of this problem is also Np-complete. In the part one, we have considered there are two fixed vertices to find the restricted Steiner tree problem. Naturally, we consider there are three fixed vertices to find the restricted Steiner tree problem. And we also use the geometric method to solve such the problem.

Exact Analytical Solutions in Three-Body Problems and Model of Neutrino Generator

Directory of Open Access Journals (Sweden)

Takibayev N.Zh.

2010-04-01

Full Text Available Exact analytic solutions are obtained in three-body problem for the scattering of light particle on the subsystem of two fixed centers in the case when pair potentials have a separable form. Solutions show an appearance of new resonance states and dependence of resonance energy and width on distance between two fixed centers. The approach of exact analytical solutions is expanded to the cases when two-body scattering amplitudes have the Breit-Wigner’s form and employed for description of neutron resonance scattering on subsystem of two heavy nuclei fixed in nodes of crystalline lattice. It is shown that some resonance states have widths close to zero at the certain values of distance between two heavy scatterer centers, this gives the possibility of transitions between states. One of these transitions between three-body resonance states could be connected with process of electron capture by proton with formation of neutron and emission of neutrino. This exoenergic process leading to the cooling of star without nuclear reactions is discussed.

Three-Body Potentials in α-Particle Model of Light Nuclei

International Nuclear Information System (INIS)

Ishikawa, Souichi

2017-01-01

In three-body model calculations of atomic nuclei, e.g., the "1"2C nucleus as α-α-α system and the "9Be nucleus as α-α-n system, the Hamiltonians of the systems consisting of two- and three-body potentials are important inputs. However, our knowledge of three-body potentials is quite restricted. In this paper, I will examine a relation between α-α-α and α-α-n three-body potentials that is obtained in a simple cluster model picture, which gives a phenomenological constraint condition on the three-body potential models to be used. (author)

Illustrating chaos: a schematic discretization of the general three-body problem in Newtonian gravity

Science.gov (United States)

Leigh, Nathan W. C.; Wegsman, Shalma

2018-05-01

We present a formalism for constructing schematic diagrams to depict chaotic three-body interactions in Newtonian gravity. This is done by decomposing each interaction into a series of discrete transformations in energy- and angular momentum-space. Each time a transformation is applied, the system changes state as the particles re-distribute their energy and angular momenta. These diagrams have the virtue of containing all of the quantitative information needed to fully characterize most bound or unbound interactions through time and space, including the total duration of the interaction, the initial and final stable states in addition to every intervening temporary meta-stable state. As shown via an illustrative example for the bound case, prolonged excursions of one of the particles, which by far dominates the computational cost of the simulations, are reduced to a single discrete transformation in energy- and angular momentum-space, thereby potentially mitigating any computational expense. We further generalize our formalism to sequences of (unbound) three-body interactions, as occur in dense stellar environments during binary hardening. Finally, we provide a method for dynamically evolving entire populations of binaries via three-body scattering interactions, using a purely analytic formalism. In principle, the techniques presented here are adaptable to other three-body problems that conserve energy and angular momentum.

Three-body interactions in many-body effective field theory

International Nuclear Information System (INIS)

Furnstahl, R.J.

2004-01-01

This contribution is an advertisement for applying effective field theory (EFT) to many-body problems, including nuclei and cold atomic gases. Examples involving three-body interactions are used to illustrate how EFT's quantify and systematically eliminate model dependence, and how they make many-body calculations simpler and more powerful

Shape space figure-8 solution of three body problem with two equal masses

Science.gov (United States)

Yu, Guowei

2017-06-01

In a preprint by Montgomery (https://people.ucsc.edu/~rmont/Nbdy.html), the author attempted to prove the existence of a shape space figure-8 solution of the Newtonian three body problem with two equal masses (it looks like a figure 8 in the shape space, which is different from the famous figure-8 solution with three equal masses (Chenciner and Montgomery 2000 Ann. Math. 152 881-901)). Unfortunately there is an error in the proof and the problem is still open. Consider the α-homogeneous Newton-type potential, 1/rα, using action minimization method, we prove the existence of this solution, for α \\in (1, 2) ; for α=1 (the Newtonian potential), an extra condition is required, which unfortunately seems hard to verify at this moment.

Modified Kepler's law, escape speed, and two-body problem in modified Newtonian dynamics-like theories

International Nuclear Information System (INIS)

Zhao Hongsheng; Li Baojiu; Bienayme, Olivier

2010-01-01

We derive a simple analytical expression for the two-body force in a subclass of modified Newtonian dynamics (MOND) theories and make testable predictions in the modification to the two-body orbital period, shape, precession rate, escape speed, etc. We demonstrate the applications of the modified Kepler's law in the timing of satellite orbits around the Milky Way, and checking the feasibility of MOND in the orbit of the large Magellanic cloud, the M31 galaxy, and the merging bullet clusters. MOND appears to be consistent with satellite orbits although with a tight margin. Our results on two-bodies are also generalized to restricted three-body, many-body problems, rings, and shells.

Restrictive educational placements increase adolescent risks for students with early-starting conduct problems.

Science.gov (United States)

Powers, Christopher J; Bierman, Karen L; Coffman, Donna L

2016-08-01

Students with early-starting conduct problems often do poorly in school; they are disproportionately placed in restrictive educational placements outside of mainstream classrooms. Although intended to benefit students, research suggests that restrictive placements may exacerbate the maladjustment of youth with conduct problems. Mixed findings, small samples, and flawed designs limit the utility of existing research. This study examined the impact of restrictive educational placements on three adolescent outcomes (high school noncompletion, conduct disorder, depressive symptoms) in a sample of 861 students with early-starting conduct problems followed longitudinally from kindergarten (age 5-6). Causal modeling with propensity scores was used to adjust for confounding factors associated with restrictive placements. Analyses explored the timing of placement (elementary vs. secondary school) and moderation of impact by initial problem severity. Restrictive educational placement in secondary school (but not in elementary school) was iatrogenic, increasing the risk of high school noncompletion and the severity of adolescent conduct disorder. Negative effects were amplified for students with conduct problem behavior with less cognitive impairment. To avoid harm to students and to society, schools must find alternatives to restrictive placements for students with conduct problems in secondary school, particularly when these students do not have cognitive impairments that might warrant specialized educational supports. © 2015 Association for Child and Adolescent Mental Health.

Renormalization-group study of the four-body problem

International Nuclear Information System (INIS)

Schmidt, Richard; Moroz, Sergej

2010-01-01

We perform a renormalization-group analysis of the nonrelativistic four-boson problem by means of a simple model with pointlike three- and four-body interactions. We investigate in particular the region where the scattering length is infinite and all energies are close to the atom threshold. We find that the four-body problem behaves truly universally, independent of any four-body parameter. Our findings confirm the recent conjectures of others that the four-body problem is universal, now also from a renormalization-group perspective. We calculate the corresponding relations between the four- and three-body bound states, as well as the full bound-state spectrum and comment on the influence of effective range corrections.

Method of resonating groups in the Faddeev-Hahn equation formalism for three-body nuclear problem

CERN Document Server

Nasirov, M Z

2002-01-01

The Faddeev-Hahn equation formalism for three-body nuclear problem is considered. For solution of the equations the method of resonant groups have applied. The calculations of tritium binding energy and doublet nd-scattering length have been carried out. The results obtained shows that Faddeev-Hahn equation formalism is very simple and effective. (author)

An initial boundary value problem for modeling a piezoelectric dipolar body

Science.gov (United States)

Marin, Marin; Öchsner, Andreas

2018-03-01

This study deals with the first initial boundary value problem in elasticity of piezoelectric dipolar bodies. We consider the most general case of an anisotropic and inhomogeneous elastic body having a dipolar structure. For two different types of restrictions imposed on the problem data, we prove two results regarding the uniqueness of solution, by using a different but accessible method. Then, the mixed problem is transformed in a temporally evolutionary equation on a Hilbert space, conveniently constructed based on the problem data. With the help of a known result from the theory of semigroups of operators, the existence and uniqueness of the weak solution for this equation are proved.

Inchworm movement of two rings switching onto a thread by biased Brownian diffusion represent a three-body problem.

Science.gov (United States)

Benson, Christopher R; Maffeo, Christopher; Fatila, Elisabeth M; Liu, Yun; Sheetz, Edward G; Aksimentiev, Aleksei; Singharoy, Abhishek; Flood, Amar H

2018-05-07

The coordinated motion of many individual components underpins the operation of all machines. However, despite generations of experience in engineering, understanding the motion of three or more coupled components remains a challenge, known since the time of Newton as the "three-body problem." Here, we describe, quantify, and simulate a molecular three-body problem of threading two molecular rings onto a linear molecular thread. Specifically, we use voltage-triggered reduction of a tetrazine-based thread to capture two cyanostar macrocycles and form a [3]pseudorotaxane product. As a consequence of the noncovalent coupling between the cyanostar rings, we find the threading occurs by an unexpected and rare inchworm-like motion where one ring follows the other. The mechanism was derived from controls, analysis of cyclic voltammetry (CV) traces, and Brownian dynamics simulations. CVs from two noncovalently interacting rings match that of two covalently linked rings designed to thread via the inchworm pathway, and they deviate considerably from the CV of a macrocycle designed to thread via a stepwise pathway. Time-dependent electrochemistry provides estimates of rate constants for threading. Experimentally derived parameters (energy wells, barriers, diffusion coefficients) helped determine likely pathways of motion with rate-kinetics and Brownian dynamics simulations. Simulations verified intercomponent coupling could be separated into ring-thread interactions for kinetics, and ring-ring interactions for thermodynamics to reduce the three-body problem to a two-body one. Our findings provide a basis for high-throughput design of molecular machinery with multiple components undergoing coupled motion.

Canonical three-body angular basis

International Nuclear Information System (INIS)

Matveenko, A.V.

2001-01-01

Three-body problems are basic for the quantum mechanics of molecular, atomic, or nuclear systems. We demonstrate that their variational solution for rotational states can be greatly simplified. A special choice of coordinates (hyperspherical) and of the kinematics (body-fixed coordinate frame) allows one to choose basis functions in a form that makes the angular coupling trivial. (author)

Stability and periodicity in the Sitnikov three-body problem when primaries are oblate spheroids

Science.gov (United States)

Rahman, M. A.; Garain, D. N.; Hassan, M. R.

2015-05-01

This paper deals with the effect of oblateness of the primaries of equal masses on the series solutions of the Sitnikov problem of three bodies. Effects of oblateness have also been shown on the stability of libration points and Poincare surface of section. Here series solutions have been developed with the help of iteration process of Green's function and by the Lindstedt-Poincare method. Following Murray and Dermott (Solar System Dynamics, Cambridge University Press, Cambridge, 1999) we have checked the stability of the equilibrium points in the Sitnikov problem. Periodicity and quasi-periodicity have been examined by drawing the Poincare surfaces of section using the mathematical software.

Three-body approach to the nucleon-nucleus optical potential

International Nuclear Information System (INIS)

Tandy, P.C.; Redish, E.F.; Bolle, D.

1976-01-01

In the Watson single scattering theory of the optical potential it is customary to approximate the propagation by two-body Green functions in order to simplify calculations. The reaction mechanism being described, however, is decidedly three-body in character. The central difficulty in building three-body models for nucleon-nucleus elastic scattering is to find the proper way of imbedding the superposed three-body reaction mechanism in the many-body problem without introducing serious overcounting effects. One would also like an explicit description of the intermediate state processes responsible for absorption. In this paper a three-body approximation to the optical potential theory is presented which overcomes the overcounting problem and is capable of including the following effects: (1) the proper kinematics of the struck nucleon, (2) its binding potential, (3) the identity of target nucleons, and (4) realistic wave functions and spectroscopic factors. The three-body model for the optical potential can be extended using unitarity methods to yield a unified three-body-like model of elastic scattering, pickup, and single nucleon knockout. (Auth.)

Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction in People with Obesity.

Science.gov (United States)

Hall, Kevin D; Bemis, Thomas; Brychta, Robert; Chen, Kong Y; Courville, Amber; Crayner, Emma J; Goodwin, Stephanie; Guo, Juen; Howard, Lilian; Knuth, Nicolas D; Miller, Bernard V; Prado, Carla M; Siervo, Mario; Skarulis, Monica C; Walter, Mary; Walter, Peter J; Yannai, Laura

2015-09-01

Dietary carbohydrate restriction has been purported to cause endocrine adaptations that promote body fat loss more than dietary fat restriction. We selectively restricted dietary carbohydrate versus fat for 6 days following a 5-day baseline diet in 19 adults with obesity confined to a metabolic ward where they exercised daily. Subjects received both isocaloric diets in random order during each of two inpatient stays. Body fat loss was calculated as the difference between daily fat intake and net fat oxidation measured while residing in a metabolic chamber. Whereas carbohydrate restriction led to sustained increases in fat oxidation and loss of 53 ± 6 g/day of body fat, fat oxidation was unchanged by fat restriction, leading to 89 ± 6 g/day of fat loss, and was significantly greater than carbohydrate restriction (p = 0.002). Mathematical model simulations agreed with these data, but predicted that the body acts to minimize body fat differences with prolonged isocaloric diets varying in carbohydrate and fat. Copyright © 2015 Elsevier Inc. All rights reserved.

The effects of beta-adrenergic blockade on body composition in free-fed and diet-restricted rats.

Science.gov (United States)

Ji, L L; Doan, T D; Lennon, D L; Nagle, F J; Lardy, H A

1987-04-01

The effects of the non-selective beta-adrenergic blocking agent propranolol (known for its anti-lipolytic activity) on body composition were investigated in growing male rats on normal unrestricted diet (N = 7) and on diet restriction (N = 7, 95% of controls). Three animals in each group were injected i.p. with 30 mg propranolol per kg body weight (bw) dissolved in saline, 5 days/week. This dose attenuates exercising heart rate by 25% and exercise training-induced enzyme activity. The remaining animals received saline. Fat, glycogen, moisture and non-ether extractable residue were determined in the homogenized residue of the whole animal. After 9 weeks on the experimental regimen, bw gain was significantly lower in the diet restricted rats, whereas propranolol had no effect on the bw gain. The percentage of fat, moisture and non-ether extractable residue were unchanged by either propranolol or diet restriction. However, glycogen content was significantly lower in the beta-blocked rats either with or without diet restriction. These data indicated that neither beta-adrenergic blockade nor minimal diet restriction influences the percentage body fat, whereas body glycogen content is decreased under both conditions.

Configuration space methods in the three-nucleon problem

International Nuclear Information System (INIS)

Friar, J.L.

1985-01-01

The assumptions underlying the formulation and solution of the Schroedinger equation for three nucleons in configuration space are reviewed. Those qualitative aspects of the two-nucleon problem which play an important role in the trinucleon are discussed. The geometrical aspects of the problem are developed, and the importance of the angular momentum barrier is demonstrated. The Faddeev-Noyes formulation of the Schroedinger equation is motivated, and the boundary conditions for various three-body problems is reviewed. The method of splines is shown to provide a particularly useful numerical modelling technique for solving the Faddeev-Noyes equation. The properties of explicit trinucleon solutions for various two-body force models are discussed, and the evidence for three-body forces is reviewed. The status of calculations of trinucleon observables is discussed, and conclusions are presented. 40 refs., 14 figs

Optimization of the variational basis in the three body problem

International Nuclear Information System (INIS)

Simenog, I.V.; Pushkash, O.M.; Bestuzheva, A.B.

1995-01-01

The procedure of variational oscillator basis optimization is proposed to the calculation the energy spectra of three body systems. The hierarchy of basis functions is derived and energies of ground and excited states for three gravitating particles is obtained with high accuracy. 12 refs

Three-body molecular description of 9Be

International Nuclear Information System (INIS)

Revai, J.; Matveenko, A.V.

1979-01-01

The low lying spectrum of the 9 Be nucleus is calculated in the α+α+n three-body model. The molecular approach to this three-body problem based on the exact evalution of the two-center wave functions for separable n-α potentials is considered in detail. The numerical results are obtained in the generalized Born-Oppenheimer approximation which preserves total angular momentum and parity

An association between the internalization of body image, depressive symptoms and restrictive eating habits among young males.

Science.gov (United States)

Fortes, Leonardo de Sousa; Meireles, Juliana Fernandes Filgueiras; Paes, Santiago Tavares; Dias, Fernanda Coelho; Cipriani, Flávia Marcele; Ferreira, Maria Elisa Caputo

2015-11-01

The scope of this study was to analyze the relationship between the internalization of body image and depressive symptoms with restrictive eating habits among young males. Three hundred and eighty-three male adolescents, aged between twelve and seventeen, took part in this survey. The "Overall Internalization" and "Athletic Internalization" sub-scales taken from the Sociocultural Attitudes Towards Appearance Questionnaire-3 (SATAQ-3) were used to evaluate the internalization of body images. The Major Depression Inventory (MDI) was used to evaluate depressive symptoms. The "Diet" sub-scale from the Eating Attitudes Test (EAT-26) was used to evaluate restrictive eating habits. The logistic regression findings indicated 2.01 times greater chances of youngsters with a high level of overall internalization adopting restrictive eating habits (Wald = 6.16; p = 0.01) when compared with those with low levels. On the other hand, the regression model found no significant association between "Athletic Internalization" (Wald = 1.16; p = 0.23) and depressive symptoms (Wald = 0.81; p = 0.35) with eating restrictions. The findings made it possible to conclude that only overall internalization was related to eating restrictions among young males.

Efimov three-body states on top of a Fermi sea

International Nuclear Information System (INIS)

Nygaard, Nicolai Gayle; Zinner, Nikolaj Thomas

2014-01-01

The stabilization of Cooper pairs of bound electrons in the background of a Fermi sea is the origin of superconductivity and the paradigmatic example of the striking influence of many-body physics on few-body properties. In the quantum-mechanical three-body problem the famous Efimov effect yields unexpected scaling relations among a tower of universal states. These seemingly unrelated problems can now be studied in the same setup thanks to the success of ultracold atomic gas experiments. In light of the tremendous effect of a background Fermi sea on two-body properties, a natural question is whether a background can modify or even destroy the Efimov effect. Here we demonstrate how the generic problem of three interacting particles changes when one particle is embedded in a background Fermi sea, and show that Efimov scaling persists. It is found in a scaling that relates the three-body physics to the background density of fermionic particles

New approach to the theory of coupled πNN-NN system. III. A three-body limit

International Nuclear Information System (INIS)

Avishai, Y.; Mizutani, T.

1980-01-01

In the limit where the pion is restricted to be emitted only by the nucleon that first absorbed it, it is shown that the equations previously developed to describe the couple πNN (πd) - NN system reduce to conventional three-body equations. Specifically, it is found in this limit that the input πN p 11 amplitude which, put on-shell, is directly related to the experimental phase shift, contrary to the original equations where the direct (dressed) nucleon pole term and the non-pole part of this partial wave enter separately. The present study clarifies the limitation of pure three-body approach to the πNN-NN problems as well as suggests a rare opportunity of observing a possible resonance behavior in the non-pole part of the πN P 11 amplitude through πd experiments

Three-body unitary transformations, three-body forces, and trinucleon bound state properties

International Nuclear Information System (INIS)

Haftel, M.I.

1976-01-01

A three-body unitary transformation method for the study of three-body forces is presented. Starting with a three-body Hamiltonian with two-body forces, unitary transformations are introduced to generate Hamiltonians that have both two- and three-body forces. For cases of physical interest, the two-body forces of the altered Hamiltonians are phase equivalent (for two-body scattering) to the original and the three-body force vanishes when any interparticle distance is large. Specific examples are presented. Applications for studying the possible role of three-body forces in accounting for trinucleon bound state properties are examined. Calculations of the 3 He and 3 H charge form factors and Coulomb energy difference with hyperspherical radial transformations and with conventional N-N potentials are performed. The form factor calculations demonstrate how the proposed method can help obtain improved agreement with experiment by the introduction of appropriate three-body forces. Calculations of the Coulomb energy difference confirm previous estimates concerning charge symmetry breaking in the N-N interaction

A naturalistic examination of body checking and dietary restriction in women with anorexia nervosa.

Science.gov (United States)

Lavender, Jason M; Wonderlich, Stephen A; Crosby, Ross D; Engel, Scott G; Mitchell, James E; Crow, Scott; Peterson, Carol B; Le Grange, Daniel

2013-08-01

Body checking has been conceptualized as a behavioral manifestation of the core overvaluation of eating, shape, and weight concerns underlying eating disorder psychopathology. Cognitive-behavioral theories suggest that body checking behaviors may function to maintain dietary restriction. The current study examined the association between body checking frequency and dietary restriction among women with anorexia nervosa (AN) in the natural environment. Women (N = 118) with full or partial AN completed baseline clinical interviews and a two-week ecological momentary assessment protocol, during which they reported on body checking behaviors (i.e., checking whether one's thighs touch; checking joints/bones for fat) and dietary restriction (i.e., 8 waking hours without eating; consuming less than 1200 calories per day). Average daily body checking frequency was positively associated with baseline eating disorder symptoms and body mass index. Daily body checking frequency was associated with both forms of dietary restriction on the same day, as well as the following day. Results support the theorized association between body checking and overvaluation of shape and weight, and suggest that targeting such behaviors in treatment may have utility in reducing dietary restriction. Copyright © 2013 Elsevier Ltd. All rights reserved.

Protein restriction does not affect body temperature pattern in female mice.

Science.gov (United States)

Kato, Goro A; Shichijo, Hiroki; Takahashi, Toshihiro; Shinohara, Akio; Morita, Tetsuo; Koshimoto, Chihiro

2017-10-30

Daily torpor is a physiological adaptation in mammals and birds characterized by a controlled reduction of metabolic rate and body temperature during the resting phase of circadian rhythms. In laboratory mice, daily torpor is induced by dietary caloric restriction. However, it is not known which nutrients are related to daily torpor expression. To determine whether dietary protein is a key factor in inducing daily torpor in mice, we fed mice a protein-restricted (PR) diet that included only one-quarter of the amount of protein but the same caloric level as a control (C) diet. We assigned six non-pregnant female ICR mice to each group and recorded their body weights and core body temperatures for 4 weeks. Body weights in the C group increased, but those in the PR group remained steady or decreased. Mice in both groups did not show daily torpor, but most mice in a food-restricted group (n=6) supplied with 80% of the calories given to the C group exhibited decreased body weights and frequently displayed daily torpor. This suggests that protein restriction is not a trigger of daily torpor; torpid animals can conserve their internal energy, but torpor may not play a significant role in conserving internal protein. Thus, opportunistic daily torpor in mice may function in energy conservation rather than protein saving.

Restriction techniques for the unit-commitment problem with total procurement costs

International Nuclear Information System (INIS)

Kaleta, Mariusz; Toczylowski, Eugeniusz

2008-01-01

Many discrete optimization problems may be solved much easier, if the solution space can be restricted in a convenient way. For a given specific problem, the restriction techniques can be helpful if an available optimization solver, perceived as a black box, is capable of solving quickly only reduced subproblems of a limited size. For the family of hard unit-commitment problems we investigate a hierarchical search algorithm, which is based on decomposition of the problem into two subproblems. The upper-level subproblem is a relatively small decision 'kernel' of the problem that can be solved approximately by a search algorithm. We define an appropriate restricted decision space for this subproblem. The lower-level subproblem is an appropriate restriction of the original problem that can be solved efficiently by a dedicated solver. Our approach was analyzed on a set of historical data from the Polish electrical balancing market and the best known solutions were improved by the average of about 2-5%

A non-orthogonal harmonic-oscillator basis for three-body problems

International Nuclear Information System (INIS)

Agrello, D.A.; Aguilera-Navarro, V.C.; Chacon, E.

1979-01-01

A set of harmonic-oscillator states suitable for the representation of the wave function of the bound states of a system of three identical particles, is presented. As an illustration of the possibilities of the states defined in this paper, they are applied in a variational determination of the lowest symmetric S state of 12 C, in the model of three structureless α particles interacting through the Coulomb force plus a phenomenological two-body force. (author) [pt

Identification of high school students' ability level of constructing free body diagrams to solve restricted and structured response items in force matter

Science.gov (United States)

Rahmaniar, Andinisa; Rusnayati, Heni; Sutiadi, Asep

2017-05-01

While solving physics problem particularly in force matter, it is needed to have the ability of constructing free body diagrams which can help students to analyse every force which acts on an object, the length of its vector and the naming of its force. Mix method was used to explain the result without any special treatment to participants. The participants were high school students in first grade totals 35 students. The purpose of this study is to identify students' ability level of constructing free body diagrams in solving restricted and structured response items. Considering of two types of test, every student would be classified into four levels ability of constructing free body diagrams which is every level has different characteristic and some students were interviewed while solving test in order to know how students solve the problem. The result showed students' ability of constructing free body diagrams on restricted response items about 34.86% included in no evidence of level, 24.11% inadequate level, 29.14% needs improvement level and 4.0% adequate level. On structured response items is about 16.59% included no evidence of level, 23.99% inadequate level, 36% needs improvement level, and 13.71% adequate level. Researcher found that students who constructed free body diagrams first and constructed free body diagrams correctly were more successful in solving restricted and structured response items.

Effective two-body equations for the four-body problem with exact treatment of (2+2)-subsystem contributions

International Nuclear Information System (INIS)

Haberzettl, H.; Sandhas, W.

1981-01-01

Noclear reactions: Four-body problem. Effective two-body equations with exact (2+2)-subsystem contributions. Relation to field-theoretical model by Fonseca and Shanley. Three-body propagator with exchange effects. (orig.)

Three-body force in the three-nucleon system

International Nuclear Information System (INIS)

Gibson, B.F.

1986-01-01

A brief summary of the symposium is presented. Three-nucleon force models are discussed, including the two-pion exchange potential, NN-ΔN coupled-channels model, and phenomenological parametrization. Relevant experimental data and model calculations are discussed including form factors, binding energies, charge radii, and charge density for 3 H and 3 He. A calculation of the EMC effect for 3 He is also made using Sasakawa's wave function and compared to experimental data obtained at SLAC. The paper ends with discussions of proton-deuteron scattering, investigations at intermediate energies, and QCD efforts to understand the three-body problem

The hyperspherical-harmonics expansion method and the integral-equation approach to solving the few-body problem in momentum space

International Nuclear Information System (INIS)

Liu, F.-Q.; Lim, T.K.

1988-01-01

The Faddeev and Faddeev-Yakubovsky equations for three- and four-body systems are solved by applying the hyperspherical-harmonics expansion to them in momentum space. This coupling of two popular approaches to the few-body problem together with the use of the so-called Raynal-Revai transformation, which relates hyperspherical functions, allows the few-body equations to be written as one-dimensional coupled integral equations. Numerical solutions for these are achieved through standard matrix methods; these are made straightforward, because a second transformation renders potential multipoles easily calculable. For sample potentials and a restricted size of matrix in each case, the binding energies extracted match those previously obtained in solving the Schroedinger equation through the hyperspherical-harmonics expansion in coordinate space. 9 refs

Restriction enzyme body doubles and PCR cloning: on the general use of type IIs restriction enzymes for cloning.

Science.gov (United States)

Tóth, Eszter; Huszár, Krisztina; Bencsura, Petra; Kulcsár, Péter István; Vodicska, Barbara; Nyeste, Antal; Welker, Zsombor; Tóth, Szilvia; Welker, Ervin

2014-01-01

The procedure described here allows the cloning of PCR fragments containing a recognition site of the restriction endonuclease (Type IIP) used for cloning in the sequence of the insert. A Type IIS endonuclease--a Body Double of the Type IIP enzyme--is used to generate the same protruding palindrome. Thus, the insert can be cloned to the Type IIP site of the vector without digesting the PCR product with the same Type IIP enzyme. We achieve this by incorporating the recognition site of a Type IIS restriction enzyme that cleaves the DNA outside of its recognition site in the PCR primer in such a way that the cutting positions straddle the desired overhang sequence. Digestion of the PCR product by the Body Double generates the required overhang. Hitherto the use of Type IIS restriction enzymes in cloning reactions has only been used for special applications, the approach presented here makes Type IIS enzymes as useful as Type IIP enzymes for general cloning purposes. To assist in finding Body Double enzymes, we summarised the available Type IIS enzymes which are potentially useful for Body Double cloning and created an online program (http://group.szbk.u-szeged.hu/welkergr/body_double/index.html) for the selection of suitable Body Double enzymes and the design of the appropriate primers.

Quasi-Three Body Systems: Properties and Scattering

International Nuclear Information System (INIS)

Amusia, M. Ya.

2017-01-01

We investigate systems of three mutually interacting particles with masses m e , m μ , M that obey the following inequality m e ≪ m μ ≪ M. Then the three-body problem reduces to the two-body scattering or structure of m e in the field of the pseudo-nucleus m μ M. We calculate analytically the properties of considered systems, such as the scattering cross-sections, hyperfine splitting, Auger decay of exited states and Lamb shifts, presenting them as expansions in powers of the parameter β=m e /m μ ≪1. (author)

Explicit demonstration of the convergence of the close-coupling method for a Coulomb three-body problem

International Nuclear Information System (INIS)

Bray, I.; Stelbovics, A.T.

1992-01-01

Convergence as a function of the number of states is studied and demonstrated for the Poet-Temkin model of electron-hydrogen scattering. In this Coulomb three-body problem only the l=0 partial waves are treated. By taking as many as thirty target states, obtained by diagonalizing the target Hamiltonian in a Laguerre basis, complete agreement with the smooth results of Poet is obtained at all energies. We show that the often-encountered pseudoresonance features in the cross sections are simply an indication of an inadequate target state representation

On the special relativistic two-body problem

International Nuclear Information System (INIS)

Afanas'ev, G.N.; Asanov, R.A.

1979-01-01

The Poincare method is applied to the consideration of the two-body problem within the Special Relativity. The formulation of the theory contains two arbitrary functions of the Lorentz invariants. A specific choice of these functions leads to the correct description of three crucial experiments of the General Relativity. The expansion on the inverse powers of the light velocity being performed, the approximate Lorentz covariant two-body equations without retardation effects are obtained

Three-body vertices with two-body techniques

International Nuclear Information System (INIS)

Mitra, A.N.; Sharma, V.K.

1976-01-01

It has long been recognized that vertex functions for few particle systems provide a convenient medium for the analysis of reactions in the language of Feynman diagrams, analogously to elementary particle processes. The development of three-particle theory during the last decade has provided considerably more impetus for the use of the language of three-body vertex functions through the possibility of their 'exact' evaluations with only two-body input. While three-body vertices are probably superfluous for the description of only three-body processes (for which exact amplitudes are already available) their practical usefulness often extends to reactions involving more than three-particle systems (for which 'exact' amplitudes are still a distant goal), as long as such systems can be meaningfully described in terms of not more than three particles playing the active role. This paper investigates a simplified construction of three-body vertices. This must check against their standard definition as overlap integral. Unfortunately this definition involves a non-trivial normalization of three-body wave functions with realistic NN potentials, and has little practical scope for extension beyond A=3. (Auth.)

Internal or shape coordinates in the n-body problem

International Nuclear Information System (INIS)

Littlejohn, R.G.; Reinsch, M.

1995-01-01

The construction of global shape coordinates for the n-body problem is considered. Special attention is given to the three- and four-body problems. Quantities, including candidates for coordinates, are organized according to their transformation properties under so-called democracy transformations (orthogonal transformations of Jacobi vectors). Important submanifolds of shape space are identified and their topology studied, including the manifolds upon which shapes are coplanar or collinear, and the manifolds upon which the moment of inertia tensor is degenerate

Efimov three-body states on top of a Fermi sea

DEFF Research Database (Denmark)

Nygaard, Nicolai Gayle; Zinner, Nikolaj Thomas

2014-01-01

The stabilization of Cooper pairs of bound electrons in the background of a Fermi sea is the origin of superconductivity and the paradigmatic example of the striking influence of many-body physics on few-body properties. In the quantum-mechanical three-body problem the famous Efimov effect yields...

Effective theories of scattering with an attractive inverse-square potential and the three-body problem

International Nuclear Information System (INIS)

Barford, Thomas; Birse, Michael C

2005-01-01

A distorted-wave version of the renormalization group is applied to scattering by an inverse-square potential and to three-body systems. In attractive three-body systems, the short-distance wavefunction satisfies a Schroedinger equation with an attractive inverse-square potential, as shown by Efimov. The resulting oscillatory behaviour controls the renormalization of the three-body interactions, with the renormalization-group flow tending to a limit cycle as the cut-off is lowered. The approach used here leads to single-valued potentials with discontinuities as the bound states are cut off. The perturbations around the cycle start with a marginal term whose effect is simply to change the phase of the short-distance oscillations, or the self-adjoint extension of the singular Hamiltonian. The full power counting in terms of the energy and two-body scattering length is constructed for short-range three-body forces

On Out of Plane Equilibrium Points in Photo-Gravitational Restricted ...

Indian Academy of Sciences (India)

Abstract. We have investigated the out of plane equilibrium points of a passive micron size particle and their stability in the field of radiating binary stellar systems Krüger-60, RW-Monocerotis within the framework of photo-gravitational circular restricted three-body problem. We find that the out of plane equilibrium points (Li,i ...

On some special cases of the restricted assignment problem

NARCIS (Netherlands)

Wang, C. (Chao); R.A. Sitters (René)

2016-01-01

textabstractWe consider some special cases of the restricted assignment problem. In this scheduling problem on parallel machines, any job j can only be assigned to one of the machines in its given subset Mj of machines. We give an LP-formulation for the problem with two job sizes and show that it

A psychiatric dialogue on the mind-body problem.

Science.gov (United States)

Kendler, K S

2001-07-01

Of all the human professions, psychiatry is most centrally concerned with the relationship of mind and brain. In many clinical interactions, psychiatrists need to consider both subjective mental experiences and objective aspects of brain function. This article attempts to summarize, in the form of a dialogue between a philosophically informed attending psychiatrist and three residents, the major philosophical positions on the mind-body problem. The positions reviewed include the following: substance dualism, property dualism, type identity, token identity, functionalism, eliminative materialism, and explanatory dualism. This essay seeks to provide a brief user-friendly introduction, from a psychiatric perspective, to current thinking about the mind-body problem.

A Study of Single- and Double-Averaged Second-Order Models to Evaluate Third-Body Perturbation Considering Elliptic Orbits for the Perturbing Body

Directory of Open Access Journals (Sweden)

R. C. Domingos

2013-01-01

Full Text Available The equations for the variations of the Keplerian elements of the orbit of a spacecraft perturbed by a third body are developed using a single average over the motion of the spacecraft, considering an elliptic orbit for the disturbing body. A comparison is made between this approach and the more used double averaged technique, as well as with the full elliptic restricted three-body problem. The disturbing function is expanded in Legendre polynomials up to the second order in both cases. The equations of motion are obtained from the planetary equations, and several numerical simulations are made to show the evolution of the orbit of the spacecraft. Some characteristics known from the circular perturbing body are studied: circular, elliptic equatorial, and frozen orbits. Different initial eccentricities for the perturbed body are considered, since the effect of this variable is one of the goals of the present study. The results show the impact of this parameter as well as the differences between both models compared to the full elliptic restricted three-body problem. Regions below, near, and above the critical angle of the third-body perturbation are considered, as well as different altitudes for the orbit of the spacecraft.

Hip-hop solutions of the 2N-body problem

Science.gov (United States)

Barrabés, Esther; Cors, Josep Maria; Pinyol, Conxita; Soler, Jaume

2006-05-01

Hip-hop solutions of the 2N-body problem with equal masses are shown to exist using an analytic continuation argument. These solutions are close to planar regular 2N-gon relative equilibria with small vertical oscillations. For fixed N, an infinity of these solutions are three-dimensional choreographies, with all the bodies moving along the same closed curve in the inertial frame.

41 CFR 102-75.1015 - Are there any restrictions on Federal agencies concerning property donations to public bodies?

Science.gov (United States)

2010-07-01

... restrictions on Federal agencies concerning property donations to public bodies? 102-75.1015 Section 102-75... Donation to Public Bodies Restrictions § 102-75.1015 Are there any restrictions on Federal agencies concerning property donations to public bodies? Yes, Federal agencies must obtain prior concurrence of GSA...

Level of energy restriction alters body condition score and morphometric profile in obese Shetland ponies.

Science.gov (United States)

Bruynsteen, L; Moons, C P H; Janssens, G P J; Harris, P A; Vandevelde, K; Lefère, L; Duchateau, L; Hesta, M

2015-10-01

Due to the high prevalence of obesity in some horses and ponies (especially in the leisure horse sector), effective and safe weight loss strategies are required. The present study evaluated the effect of two different energy restriction rates on physical, morphometric and welfare parameters in 18 obese (body condition score [BCS] 7-9/9) Shetland geldings. The trial was divided into three periods: (1) a 4 week adaptation period, during which the maintenance energy intakes to maintain a stable obese bodyweight were determined (100% MERob); (2) a 16.5-week weight loss period during which the ponies were randomly divided into three groups (n = 6/group) comprising a control group (CONTROL), moderate energy restricted (MOD), and severe energy restricted (SEV) groups that were respectively fed at 100%, 80% and 60% of their individual MERob; and (3) a 3 week follow up period in which the ponies were again fed at their outset individual 100% MERob. Between the start and end of the weight loss period, significant pairwise differences between the three treatment groups were seen for bodyweight, BCS, heart girth, belly girth, and relative ultrasound fat depth at the level of loin and ribs at several time points (P < 0.05). The higher energy restriction was associated with a faster decrease in BCS, tail head, and heart plus belly girth, but no gastric ulcers or stereotypic behaviours were seen. Copyright © 2015 Elsevier Ltd. All rights reserved.

Analytical treatment of Coriolis coupling for three-body systems

Energy Technology Data Exchange (ETDEWEB)

Poirier, Bill

2005-01-31

In a previous article [J. Chem. Phys. 108 (1998) 5216], an efficient method was presented for performing 'exact' quantum calculations for the three-body rovibrational Hamiltonian, within the helicity-conserving approximation. This approach makes use of a certain three-body ''effective potential,'' enabling the same bend angle basis set to be employed for all values of the rotational quantum numbers, J, K and M. In the present work, the method is extended to incorporate Coriolis coupling, for which the relevant matrix elements are derived exactly. These can be used to solve the full three-body rovibrational problem, in the standard Jacobi coordinate vector embedding. Generalization of the method for coupled kinetic energy operators arising from other coordinate systems, embeddings, and/or system sizes, is also discussed.

Analysis of Periodic Orbits about the Triangular Solutions of the Restricted Sum-Jupiter and Earth-Moon Problem

Directory of Open Access Journals (Sweden)

Sang-Young Park

1988-12-01

Full Text Available Using the numerical solution in the plane restricted problem of three bodies, about 490 periodic orbits are computed numerically around the L5 of Sun-Jupiter and about 1600 periodic orbits also be done around the L5 of Earth-Moon system. As period increase, the energy and the shape of periodic orbits increase around the L5 of Sun-Jupiter system. But, in Earth-Moon system, the complex shapes and dents appear around the L5 and periodic orbits intersect one another in the place where dents are shown. And there is a region that three different periodic orbits exist with the same period in this region. The regions can exist around the L5 of Sun-Jupiter system where periodic orbit can be unstable by perturbation of other force besides the gravitational force of Jupiter. These regions which is close to L5 are a ~5.12 AU and a ~5.29 AU. The Trojan asteroids that have a small eccentricity and inclination can not exist in this region.

Contact parameters in two dimensions for general three-body systems

DEFF Research Database (Denmark)

F. Bellotti, F.; Frederico, T.; T. Yamashita, M.

2014-01-01

a subsystem is composed of two identical non-interacting particles. We also show that the three-body contact parameter is negligible in the case of one non-interacting subsystem compared to the situation where all subsystem are bound. As example, we present results for mixtures of Lithium with two Cesium......We study the two dimensional three-body problem in the general case of three distinguishable particles interacting through zero-range potentials. The Faddeev decomposition is used to write the momentum-space wave function. We show that the large-momentum asymptotic spectator function has the same...... to obtain two- and three-body contact parameters. We specialize from the general cases to examples of two identical, interacting or non-interacting, particles. We find that the two-body contact parameter is not a universal constant in the general case and show that the universality is recovered when...

Framing the Mind-Body Problem in Contemporary Neuroscientific and Sunni Islamic Theological Discourse.

Science.gov (United States)

Qazi, Faisal; Fette, Don; Jafri, Syed S; I Padela, Aasim

2018-07-01

Famously posed by seventeenth-century French philosopher René Descartes, the mind-body problem remains unresolved in western philosophy and science, with both disciplines unable to move convincingly beyond the dualistic model. The persistence of dualism calls for a reframing of the problem through interdisciplinary modes of inquiry that include non-western points of view. One such perspective is Islamic theology of the soul, which, while approaching the problem from a distinct point of view, also adopts a position commensurate with (substance) dualism. Using this point of convergence as a conceptual starting point, we argue that bringing into dialogue contemporary neuroscientific, philosophy of mind, and Sunni Islamic theological discourses may provide a fruitful way of reframing the age-old mind-body problem. This paper provides an overview of how these three discourses have approached the issue of the mind-body (-soul) problem. Juxtaposing these three discourses, we hope, may ignite further scholarly dialogue and investigation.

The research of the coupled orbital-attitude controlled motion of celestial body in the neighborhood of the collinear libration point L1

Science.gov (United States)

Shmyrov, A.; Shmyrov, V.; Shymanchuk, D.

2017-10-01

This article considers the motion of a celestial body within the restricted three-body problem of the Sun-Earth system. The equations of controlled coupled attitude-orbit motion in the neighborhood of collinear libration point L1 are investigated. The translational orbital motion of a celestial body is described using Hill's equations of circular restricted three-body problem of the Sun-Earth system. Rotational orbital motion is described using Euler's dynamic equations and quaternion kinematic equation. We investigate the problem of stability of celestial body rotational orbital motion in relative equilibrium positions and stabilization of celestial body rotational orbital motion with proposed control laws in the neighborhood of collinear libration point L1. To study stabilization problem, Lyapunov function is constructed in the form of the sum of the kinetic energy and special "kinematic function" of the Rodriguez-Hamiltonian parameters. Numerical modeling of the controlled rotational motion of a celestial body at libration point L1 is carried out. The numerical characteristics of the control parameters and rotational motion are given.

Three-body forces for electrons by the S-matrix method

International Nuclear Information System (INIS)

Margaritelli, R.

1989-01-01

A electromagnetic three-body potential between eletrons is derived by the S-matrix method. This potential can be compared up to a certain point with other electromagnetic potentials (obtained by other methods) encountered in the literature. However, since the potential derived here is far more complete than others, this turns direct comparison with the potentials found in the literature somewhat difficult. These calculations allow a better understanding of the S-matrix method as applied to problems which involve the calculations of three-body nuclear forces (these calculations are performed in order to understand the 3 He form factor). Furthermore, these results enable us to decide between two discrepant works which derive the two-pion exchange three-body potential, both by the S-matrix method. (author) [pt

Few-body problem in celestial mechanics

Energy Technology Data Exchange (ETDEWEB)

Dermott, S F [Cornell Univ., Ithaca, NY (USA). Center for Radiophysics and Space Research

1984-03-26

The approaches taken by solar system dynamicists to various outstanding problems has changed considerably in recent years. Some problems for which few-body approaches have been tried in the past are now thought to involve collective phenomena. Observed features in Saturn's rings associated with resonances are examples. On the other hand, the problem of the origin of the Kirkwood gaps in the asteroid belt, for which a number of a many-body approaches (involving collisions or gas friction) have been tried, probably has a few-body solution and may involve chaos.

Stripping reactions in a three-body system. Comparison of DWBA and exact solutions

International Nuclear Information System (INIS)

Brinati, J.R.

1976-01-01

Stripping reactions 'a estados no continuo' are studied in a three particle system. Since the three-body problem has an exact treatment, comparison will be made between the exact solution and the DWBA model solution. This problem is more complex in the continuous case, as shown in the convergence problem of the standard DWBA amplitude radial integral

Geometrical themes inspired by the n-body problem

CERN Document Server

Herrera, Haydeé; Herrera, Rafael

2018-01-01

Presenting a selection of recent developments in geometrical problems inspired by the N-body problem, these lecture notes offer a variety of approaches to study them, ranging from variational to dynamical, while developing new insights, making geometrical and topological detours, and providing historical references. A. Guillot’s notes aim to describe differential equations in the complex domain, motivated by the evolution of N particles moving on the plane subject to the influence of a magnetic field. Guillot studies such differential equations using different geometric structures on complex curves (in the sense of W. Thurston) in order to find isochronicity conditions.   R. Montgomery’s notes deal with a version of the planar Newtonian three-body equation. Namely, he investigates the problem of whether every free homotopy class is realized by a periodic geodesic. The solution involves geometry, dynamical systems, and the McGehee blow-up. A novelty of the approach is the use of energy-balance in order t...

Nuclear structure with unitarily transformed two-body plus phenomenological three-body interactions

Energy Technology Data Exchange (ETDEWEB)

Guenther, Anneke

2011-02-02

The importance of three-nucleon forces for a variety of nuclear structure phenomena is apparent in various investigations. This thesis provides a first step towards the inclusion of realistic three-nucleon forces by studying simple phenomenological threebody interactions. The Unitary Correlation Operator Method (UCOM) and the Similarity Renormalization Group (SRG) provide two different approaches to derive soft phase-shift equivalent nucleon-nucleon (NN) interactions via unitary transformations. Although their motivations are quite different the NN interactions obtained with the two methods exhibit some similarities. The application of the UCOM- or SRG-transformed Argonne V18 potential in the Hartree-Fock (HF) approximation and including the second-order energy corrections emerging from many-body perturbation theory (MBPT) reveals that the systematics of experimental ground-state energies can be reproduced by some of the interactions considering a series of closed-shell nuclei across the whole nuclear chart. However, charge radii are systematically underestimated, especially for intermediate and heavy nuclei. This discrepancy to experimental data is expected to result from neglected three-nucleon interactions. As first ansatz for a three-nucleon force, we consider a finite-range three-body interaction of Gaussian shape. Its influence on ground-state energies and charge radii is discussed in detail on the basis of HF plus MBPT calculations and shows a significant improvement in the description of experimental data. As the handling of the Gaussian three-body interaction is time-extensive, we show that it can be replaced by a regularized three-body contact interaction exhibiting a very similar behavior. An extensive study characterizes its properties in detail and confirms the improvements with respect to nuclear properties. To take into account information of an exact numerical solution of the nuclear eigenvalue problem, the No-Core Shell Model is applied to

Three-body segment musculoskeletal model of the upper limb

Directory of Open Access Journals (Sweden)

Valdmanová L.

2013-06-01

Full Text Available The main aim is to create a computational three-body segment model of an upper limb of a human body for determination of muscle forces generated to keep a given loaded upper limb position. The model consists of three segments representing arm, forearm, hand and of all major muscles connected to the segments. Muscle origins and insertions determination corresponds to a real anatomy. Muscle behaviour is defined according to the Hill-type muscle model consisting of contractile and viscoelastic element. The upper limb is presented by a system of three rigid bars connected by rotational joints. The whole limb is fixed to the frame in the shoulder joint. A static balance problem is solved by principle of virtual work. The system of equation describing the musculoskeletal system is overdetermined because more muscles than necessary contribute to get the concrete upper limb position. Hence the mathematical problem is solved by an optimization method searching the least energetically-consuming solution. The upper limb computational model is verified by electromyography of the biceps brachii muscle.

The body force in a three-dimensional Lame system identification and regularization

DEFF Research Database (Denmark)

Trong, Dang Duc; Phan, Thanh Nam; Thuc, Phung Trong

2012-01-01

Let a three-dimensional isotropic elastic body be described by the Lamé system with the body force of the form F(x, t) = (t)f (x), where is known. We consider the problem of determining the unknown spatial term f (x) of the body force when the surface stress history is given...

More than six hundred new families of Newtonian periodic planar collisionless three-body orbits

Science.gov (United States)

Li, XiaoMing; Liao, ShiJun

2017-12-01

The famous three-body problem can be traced back to Isaac Newton in the 1680s. In the 300 years since this "three-body problem" was first recognized, only three families of periodic solutions had been found, until 2013 when Šuvakov and Dmitrašinović [Phys. Rev. Lett. 110, 114301 (2013)] made a breakthrough to numerically find 13 new distinct periodic orbits, which belong to 11 new families of Newtonian planar three-body problem with equal mass and zero angular momentum. In this paper, we numerically obtain 695 families of Newtonian periodic planar collisionless orbits of three-body system with equal mass and zero angular momentum in case of initial conditions with isosceles collinear configuration, including the well-known figure-eight family found by Moore in 1993, the 11 families found by Šuvakov and Dmitrašinović in 2013, and more than 600 new families that have never been reported, to the best of our knowledge. With the definition of the average period T = T/L f, where L f is the length of the so-called "free group element", these 695 families suggest that there should exist the quasi Kepler's third law T* ≈ 2:433 ± 0:075 for the considered case, where T ≈ = T | E|3/2 is the scale-invariant average period and E is its total kinetic and potential energy, respectively. The movies of these 695 periodic orbits in the real space and the corresponding close curves on the "shape sphere" can be found via the website: http://numericaltank.sjtu.edu.cn/three-body/three-body.htm.

Oblique water entry of a three dimensional body

Directory of Open Access Journals (Sweden)

Scolan Yves-Marie

2014-12-01

Full Text Available The problem of the oblique water entry of a three dimensional body is considered. Wagner theory is the theoretical framework. Applications are discussed for an elliptic paraboloid entering an initially flat free surface. A dedicated experimental campaign yields a data base for comparisons. In the present analysis, pressure, force and dynamics of the wetted surface expansion are assessed.

Feeding period restriction alters the expression of peripheral circadian rhythm genes without changing body weight in mice.

Directory of Open Access Journals (Sweden)

Hagoon Jang

Full Text Available Accumulating evidence suggests that the circadian clock is closely associated with metabolic regulation. However, whether an impaired circadian clock is a direct cause of metabolic dysregulation such as body weight gain is not clearly understood. In this study, we demonstrate that body weight gain in mice is not significantly changed by restricting feeding period to daytime or nighttime. The expression of peripheral circadian clock genes was altered by feeding period restriction, while the expression of light-regulated hypothalamic circadian clock genes was unaffected by either a normal chow diet (NCD or a high-fat diet (HFD. In the liver, the expression pattern of circadian clock genes, including Bmal1, Clock, and Per2, was changed by different feeding period restrictions. Moreover, the expression of lipogenic genes, gluconeogenic genes, and fatty acid oxidation-related genes in the liver was also altered by feeding period restriction. Given that feeding period restriction does not affect body weight gain with a NCD or HFD, it is likely that the amount of food consumed might be a crucial factor in determining body weight. Collectively, these data suggest that feeding period restriction modulates the expression of peripheral circadian clock genes, which is uncoupled from light-sensitive hypothalamic circadian clock genes.

Extrauterine growth restriction: Universal problem among premature infants

Directory of Open Access Journals (Sweden)

Brunnella Alcantara Chagas de FREITAS

2016-02-01

Full Text Available ABSTRACT Objective: To analyze the growth rate of premature infants in the first weeks of life and factors associated with extrauterine growth restriction. Methods: This is a cross-sectional study of 254 premature infants in a neonatal intensive care unit conducted from January 1, 2008 to December 31, 2010. Infants who died or had malformations incompatible with life were excluded. Median weight curves according to gestational age were constructed for the first four weeks of life. The Fenton growth chart calculations provided the weight Z-scores. Extrauterine growth restriction was defined as corrected weight-for-age Z-score ≤-2. Perinatal, morbidity, and health care variables were analyzed. The Poisson regression model yielded the prevalenceratios . Associations between extrauterine growth restriction and the perinatal, morbidity, and care variables were investigated. Poisson regression controlled possible confounding factors. Results: The frequency of extrauterine growth restriction was 24.0%. Most (85.0% small-for-gestational-age infants developed extrauterine growth restriction; 55.3% of extrauterine growth restriction cases involved small-for-gestational-age infants. Premature infants with gestational age >32 weeks did not recover the median birth weight until the third week of life and had a higher frequency of small-for-gestational-age. The Z-scores of non-small-for-gestational-age infants decreased more after birth than those of small-for-gestational-age infants. extrauterine growth restriction was associated with small-for-gestational-age (PR=6.14; 95%CI=3.33-11.33;p <0.001 and time without enteral diet (PR=1.08; 95%CI=1.04-1.13; p =0.010. Conclusion: Extrauterine growth restriction occurs in premature infants of all gestational age. The participation of small-for-gestational-age and nutritional practices in its genesis is noteworthy. We suggest prospective studies of all premature infants. The implementation of best care practices

Three-dimensional problems in the theory of cracks

International Nuclear Information System (INIS)

Panasyuk, V.V.; Andrejkiv, A.E.; Stadnik, M.M.

1979-01-01

Review of the main mechanical conceptions and mathematic methods, used in solving of spatial problems of the theory of cracks is given. At that, cases of effects upon a body of force static and cyclic and geometrically variable temperature fields are considered. The main calculation models of the theory of cracks are characterized in detail. Other models, derived from these ones and used in solving the above problems are also mentioned. Analysis and synthesis of the most general mathematic methods of solving three-dimensional problems of the theory of cracks are made. Besides precise methods, approximate ones are also presented, being efficient enough in engineering practice

The Tucson-Melbourne Three-Body Force in a Translationally-Invariant Harmonic Oscillator Basis

Science.gov (United States)

Marsden, David; Navratil, Petr; Barrett, Bruce

2000-09-01

A translationally-invariant three-body basis set has been employed in shell model calculations on ^3H and ^3He including the Tucson-Melbourne form of the real nuclear three-body force. The basis consists of harmonic oscillators in Jacobi coordinates, explicitly avoiding the centre of mass drift problem in the calculations. The derivation of the three-body matrix elements and the results of large basis effective interaction shell model calculations will be presented. J. L. Friar, B. F. Gibson, G. L. Payne and S. A. Coon; Few Body Systems 5, 13 (1988) P. Navratil, G.P. Kamuntavicius and B.R. Barrett; Phys. Rev. C. 61, 044001 (2000)

The Mind-Body Problem.

Science.gov (United States)

Fodor, Jerry A.

1981-01-01

Describes several different philosophies of mind with each philosophy's explanation of the mind-body problem. Philosophies discussed include dualism, materialism, functionalism, radical behaviorism, logical behaviorism and central-state identity. (DS)

Three-body forces: a status report

International Nuclear Information System (INIS)

Coon, S.A.

1976-01-01

Real three-body forces due to meson exchange are distinguished from effective three-body interactions of a nuclear Hamiltonian. The long-range part of the real three-body force is proportional to the off-mass-shell sup(PI)N scattering amplitude. Its contribution to the binding energy of nuclear matter is quite dependent upon the treatment of correlations (due to the two-body potential) in the three-body wave function. A recent improvemrnt in the amplitude implies a very small contribution. But, a recent improvement in the treatment of correlations implies a large contribution. Work towards including both these improvements in a single calculation is in progress. (author)

Reduction in the body content of DDE in the Mongolian gerbil treated with sucrose polyester and caloric restriction

International Nuclear Information System (INIS)

Mutter, L.C.; Blanke, R.V.; Jandacek, R.J.; Guzelian, P.S.

1988-01-01

It has previously been shown that oral administration to rats of sucrose polyester (SPE4), a nonabsorbable lipophilic binding agent, greatly stimulates the fecal excretion of coorally administered DDT5. To determine whether this agent would stimulate the excretion of persistent metabolites of DDT stored in body tissues, we treated a group of gerbils with [ 14 C]-DDT and monitored the fecal excretion of radioactivity for several months until a terminal, log-linear phase of excretion was observed. At this point, when greater than 75% of the fecal radioactivity was identified as [ 14 C]DDE, we fed the animals diets containing up to 10% sucrose polyester and found that the rate of excretion of radioactivity in the stool promptly increased two to three times as compared to the rate in the preceding control period. Some rats were subjected to a 25-50% restriction in total food allotment, but this produced no significant change in fecal excretion of total radioactivity. However, when food restriction was combined with administration of sucrose polyester, there was a dramatic, eightfold average increase in excretion of fecal radioactivity. This synergistic effect was reversed (within 24 hr) when the animals were transferred to a normal diet. Measurement of total body radioactivity confirmed that food restriction plus sucrose polyester treatment reduced the body content of the pesticide. We conclude that stimulation of intestinal excretion may offer a new approach to treatment of patients exposed to lipophilic environmental contaminants

Numerical solutions of the N-body problem

International Nuclear Information System (INIS)

Marciniak, A.

1985-01-01

Devoted to the study of numerical methods for solving the general N-body problem and related problems, this volume starts with an overview of the conventional numerical methods for solving the initial value problem. The major part of the book contains original work and features a presentation of special numerical methods conserving the constants of motion in the general N-body problem and methods conserving the Jacobi constant in the problem of motion of N bodies in a rotating frame, as well as an analysis of the applications of both (conventional and special) kinds of methods for solving these problems. For all the methods considered, the author presents algorithms which are easily programmable in any computer language. Moreover, the author compares various methods and presents adequate numerical results. The appendix contains PL/I procedures for all the special methods conserving the constants of motion. 91 refs.; 35 figs.; 41 tabs

Time-dependent restricted-active-space self-consistent-field theory for bosonic many-body systems

International Nuclear Information System (INIS)

Lévêque, Camille; Madsen, Lars Bojer

2017-01-01

We develop an ab initio time-dependent wavefunction based theory for the description of a many-body system of cold interacting bosons. Like the multi-configurational time-dependent Hartree method for bosons (MCTDHB), the theory is based on a configurational interaction Ansatz for the many-body wavefunction with time-dependent self-consistent-field orbitals. The theory generalizes the MCTDHB method by incorporating restrictions on the active space of the orbital excitations. The restrictions are specified based on the physical situation at hand. The equations of motion of this time-dependent restricted-active-space self-consistent-field (TD-RASSCF) theory are derived. The similarity between the formal development of the theory for bosons and fermions is discussed. The restrictions on the active space allow the theory to be evaluated under conditions where other wavefunction based methods due to exponential scaling in the numerical effort cannot, and to clearly identify the excitations that are important for an accurate description, significantly beyond the mean-field approach. For ground state calculations we find it to be important to allow a few particles to have the freedom to move in many orbitals, an insight facilitated by the flexibility of the restricted-active-space Ansatz . Moreover, we find that a high accuracy can be obtained by including only even excitations in the many-body self-consistent-field wavefunction. Time-dependent simulations of harmonically trapped bosons subject to a quenching of their noncontact interaction, show failure of the mean-field Gross-Pitaevskii approach within a fraction of a harmonic oscillation period. The TD-RASSCF theory remains accurate at much reduced computational cost compared to the MCTDHB method. Exploring the effect of changes of the restricted-active-space allows us to identify that even self-consistent-field excitations are mainly responsible for the accuracy of the method. (paper)

Periodic orbit-attitude solutions along planar orbits in a perturbed circular restricted three-body problem for the Earth-Moon system

Science.gov (United States)

Bucci, Lorenzo; Lavagna, Michèle; Guzzetti, Davide; Howell, Kathleen C.

2018-06-01

Interest on Large Space Structures (LSS), orbiting in strategic and possibly long-term stable locations, is nowadays increasing in the space community. LSS can serve as strategic outpost to support a variety of manned and unmanned mission, or may carry scientific payloads for astronomical observations. The paper focuses on analysing LSS in the Earth-Moon system, exploring dynamical structures that are available within a multi-body gravitational environment. Coupling between attitude and orbital dynamics is investigated, with particular interest on the gravity gradient torque exerted by the two massive attractors. First, natural periodic orbit-attitude solutions are obtained; a LSS that exploits such solutions would benefit of a naturally periodic body rotation synchronous with the orbital motion, easing the effort of the attitude control system to satisfy pointing requirements. Then, the solar radiation pressure is introduced into the fully coupled dynamical model and its effects investigated, discovering novel periodic attitude solutions. Benefits of periodic behaviours that incorporate solar radiation pressure are discussed, and analysed via the variation of some parameters (e.g reflection/absorption coefficients, position of the centre of pressure). As a final step to refine the current perturbed orbit-attitude model, a structure flexibility is also superimposed to a reference orbit-attitude rigid body motion via a simple, yet effective model. The coupling of structural vibrations and attitude motion is preliminarily explored, and allows identification of possible challenges, that may be faced to position a LSS in a periodic orbit within the Earth-Moon system.

Institutional Solutions to the ``Two-Body Problem"

Science.gov (United States)

Knezek, P.

2005-05-01

The Committee on the Status of Women (CSWA), in conjunction with the Employment Committee (EC), will hold a special session that will focus on institutional approaches to solving the ``two-body problem". In step with the national employment trend, for the majority of astronomers with partners, those partners work outside the home. This is particularly true for female astronomers, who generally are married to professionals (and often to other astronomers). Academic and professional institutions that employ the majority of astronomers are now beginning to recognize the importance of addressing what has come to be known as the ``two-body" problem in order to attract and retain the best scientists. A few of those institutions are making pioneering efforts to create pro-active approaches to the issue of dual-career couples. The special session will feature two or three speakers involved with the administration at institutions with pro-active policies. This special session will be coupled with the normal afternoon CSWA session, which will focus on the other side of the issue - how dual-career couples have successfully approached the issue at institutions that do NOT have proactive policies.

Hyperspherical functions and quantum-mechanical three-body problem with application to carbon 12

International Nuclear Information System (INIS)

Letz, H.

1975-01-01

In this work a system of three identical particles (bosons) interacting by a particular two-body force is discussed. Using the complete set of the hyperspherical functions (K-harmonics), analytical expressions for eigenvalues and wave functions of the stationary states are found. The numerical evaluation gives a level sequence for a definite pair of potential parameters similar to that of the nucleus carbon 12

Noninvasive, three-dimensional full-field body sensor for surface deformation monitoring of human body in vivo

Science.gov (United States)

Chen, Zhenning; Shao, Xinxing; He, Xiaoyuan; Wu, Jialin; Xu, Xiangyang; Zhang, Jinlin

2017-09-01

Noninvasive, three-dimensional (3-D), full-field surface deformation measurements of the human body are important for biomedical investigations. We proposed a 3-D noninvasive, full-field body sensor based on stereo digital image correlation (stereo-DIC) for surface deformation monitoring of the human body in vivo. First, by applying an improved water-transfer printing (WTP) technique to transfer optimized speckle patterns onto the skin, the body sensor was conveniently and harmlessly fabricated directly onto the human body. Then, stereo-DIC was used to achieve 3-D noncontact and noninvasive surface deformation measurements. The accuracy and efficiency of the proposed body sensor were verified and discussed by considering different complexions. Moreover, the fabrication of speckle patterns on human skin, which has always been considered a challenging problem, was shown to be feasible, effective, and harmless as a result of the improved WTP technique. An application of the proposed stereo-DIC-based body sensor was demonstrated by measuring the pulse wave velocity of human carotid artery.

Effective linear two-body method for many-body problems in atomic and nuclear physics

International Nuclear Information System (INIS)

Kim, Y.E.; Zubarev, A.L.

2000-01-01

We present an equivalent linear two-body method for the many body problem, which is based on an approximate reduction of the many-body Schroedinger equation by the use of a variational principle. The method is applied to several problems in atomic and nuclear physics. (author)

Universality in low energy three-body systems

International Nuclear Information System (INIS)

Amorim, A.E.A.; Tomio, L; Frederico, T.

1997-01-01

The renormalizability of the quantum theory of non-relativistic three-body system with zero range interaction, warranties that all the low-energy three-body properties are well defined and the low-energy two-body and only one three-body physical information are known. Considering this observation, we have shown that the conditions for the occurrence of Efimov states can be easily reached with any model of short range potential where the three-body ground state and the corresponding binding energy of the subsystems are kept fixed. This approach was applied to the recently discovered halo nuclei. (author)

Effects of food restriction across stages of juvenile and early adult development on body weight, survival and adult life history.

Science.gov (United States)

Wong, J W Y; Kölliker, M

2014-11-01

Organisms have to allocate limited resources among multiple life-history traits, which can result in physiological trade-offs, and variation in environmental conditions experienced during ontogeny can influence reproduction later in life. Food restriction may lead to an adaptive reallocation of the limited resources among traits as a phenotypically plastic adjustment, or it can act as an overall constraint with detrimental effects throughout reproductive life. In this study, we investigated experimentally the effects of food restriction during different stages of the juvenile and early adult development on body weight, survival and reproductive success in females and males of the European earwig Forficula auricularia. Individuals either received limited or unlimited access to food across three different stages of development (fully crossed) allowing us to identify sensitive periods during development and to test both additive and interactive effects of food limitation across stages on development and reproduction. Food restriction during the early and late juvenile stage had additive negative effects on juvenile survival and adult body weight. With regard to reproductive success of females which produce up to two clutches in their lifetime, restriction specifically in the late juvenile stage led to smaller first and second clutch size, lower probability of second clutch production and reduced hatching success in the second clutch. Reproductive success of females was not significantly affected when their male mates experienced food restriction during their development. Our findings in general support the 'silver-spoon' hypothesis in that food restriction during juvenile development poses constraints on development and reproduction throughout life. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

The Copenhagen problem with a quasi-homogeneous potential

Science.gov (United States)

Fakis, Demetrios; Kalvouridis, Tilemahos

2017-05-01

The Copenhagen problem is a well-known case of the famous restricted three-body problem. In this work instead of considering Newtonian potentials and forces we assume that the two primaries create a quasi-homogeneous potential, which means that we insert to the inverse square law of gravitation an inverse cube corrective term in order to approximate various phenomena as the radiation pressure of the primaries or the non-sphericity of them. Based on this new consideration we investigate the equilibrium locations of the small body and their parametric dependence, as well as the zero-velocity curves and surfaces for the planar motion, and the evolution of the regions where this motion is permitted when the Jacobian constant varies.

Classical many-body problems amenable to exact treatments (solvable and/or integrable and/or linearizable...) in one-, two- and three-dimensional space

CERN Document Server

Calogero, Francesco

2001-01-01

This book focuses on exactly treatable classical (i.e. non-quantal non-relativistic) many-body problems, as described by Newton's equation of motion for mutually interacting point particles. Most of the material is based on the author's research and is published here for the first time in book form. One of the main novelties is the treatment of problems in two- and three-dimensional space. Many related techniques are presented, e.g. the theory of generalized Lagrangian-type interpolation in higher-dimensional spaces. This book is written for students as well as for researchers; it works out detailed examples before going on to treat more general cases. Many results are presented via exercises, with clear hints pointing to their solutions.

Exercise restriction is not associated with increasing body mass index over time in patients with anomalous aortic origin of the coronary arteries.

Science.gov (United States)

Meza, James M; Elias, Matthew D; Wilder, Travis J; O'Brien, James E; Kim, Richard W; Mavroudis, Constantine; Williams, William G; Brothers, Julie; Cohen, Meryl S; McCrindle, Brian W

2017-10-01

Anomalous aortic origin of the coronary arteries is associated with exercise-induced ischaemia, leading some physicians to restrict exercise in patients with this condition. We sought to determine whether exercise restriction was associated with increasing body mass index over time. From 1998 to 2015, 440 patients ⩽30 years old were enrolled into an inception cohort. Exercise-restriction status was documented in 143 patients. Using linear mixed model repeated-measures regression, factors associated with increasing body mass index z-score over time, including exercise restriction and surgical intervention as time-varying covariates, were investigated. The 143 patients attended 558 clinic visits for which exercise-restriction status was recorded. The mean number of clinic visits per patient was 4, and the median duration of follow-up was 1.7 years (interquartile range (IQR) 0.5-4.4). The median age at first clinic visit was 10.3 years (IQR 7.1-13.9), and 71% (101/143) were males. All patients were alive at their most recent follow-up. At the first clinic visit, 54% (78/143) were exercise restricted, and restriction status changed in 34% (48/143) during follow-up. The median baseline body mass index z-score was 0.2 (IQR 0.3-0.9). In repeated-measures analysis, neither time-related exercise restriction nor its interaction with time was associated with increasing body mass index z-score. Surgical intervention and its interaction with time were associated with decreasing body mass index z-score. Although exercise restriction was not associated with increasing body mass index over time, surgical intervention was associated with decreasing body mass index z-score over time in patients with anomalous aortic origin of the coronary arteries.

Three-body unitarity with isobars revisited

Energy Technology Data Exchange (ETDEWEB)

Mai, M.; Hu, B. [The George Washington University, Washington, DC (United States); Doering, M. [The George Washington University, Washington, DC (United States); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Pilloni, A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Szczepaniak, A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Indiana University, Center for Exploration of Energy and Matter, Bloomington, IN (United States); Indiana University, Physics Department, Bloomington, IN (United States)

2017-09-15

The particle exchange model of hadron interactions can be used to describe three-body scattering under the isobar assumption. In this study we start from the 3 → 3 scattering amplitude for spinless particles, which contains an isobar-spectator scattering amplitude. Using a Bethe-Salpeter Ansatz for the latter, we derive a relativistic three-dimensional scattering equation that manifestly fulfills three-body unitarity and two-body unitarity for the sub-amplitudes. This property holds for energies above breakup and also in the presence of resonances in the sub-amplitudes. (orig.)

Effective two-body equations for the four-body problem with exact treatment of (2+2)-subsystem contributions

International Nuclear Information System (INIS)

Haberzettl, H.; Sandhas, W.

1981-01-01

Effective two-body equations for the four-body problem are derived within the general N-body theory of Alt, Grassberger, and Sandhas. In contrast to usual treatments, the final expressions do not require separable (2+2) subamplitudes but incorporate these exactly. All four-body amplitudes can be calculated from the solution of a single integral equation for the reaction (3+1)→(3+1). With single-term separable approximations for the two-particle and the (3+1) subsystem amplitudes the driving terms of the final equations are seen to reduce to those of the field-theoretical model by Fonseca and Shanley. Since our results are based on an exact and complete N-body theory, the investigation of subsystem reaction mechanisms is facilitated. As a consequence, we are led to a three-particle propagator which has the right pole behavior and includes exchange effects

Blood-flow restricted resistance training in patients with sporadic inclusion body myositis

DEFF Research Database (Denmark)

Jørgensen, A.; Aagaard, P.; Frandsen, U.

2018-01-01

Objectives: To investigate the effect of 12 weeks of low-load blood-flow restricted resistance (BFR) training on self-reported and objective physical function, and maximal muscle strength in patients with sporadic inclusion body myositis (sIBM). Method: Twenty-two patients with sIBM were randomized......), which was used to measure self-reported physical function. All patients performed physical function tests (2-Minute Walk Test, Timed Up and Go, and 30-Second Chair Stand), completed the Inclusion Body Myositis Functional Rating Scale (IBMFRS), and were tested for isolated knee extensor muscle strength...

Relativistic three-body model of pion-deuton elasic scattering

International Nuclear Information System (INIS)

Giraud, Noel.

1978-01-01

The Aaron-Amado-Young equations for the relativistic three-body problem are derived following the Blauckenbecker - Sugar method. The angular momentum reduction is carried out using suitable relative momenta. The pion-deuteron elastic scattering is calculated using the equations in which relativistic kinematics are retained only for the pion. After a general study of the observables in the energy range 25 to 256 MeV, detailed calculations are performed at 142 MeV [fr

Noninvasive, three-dimensional full-field body sensor for surface deformation monitoring of human body in vivo.

Science.gov (United States)

Chen, Zhenning; Shao, Xinxing; He, Xiaoyuan; Wu, Jialin; Xu, Xiangyang; Zhang, Jinlin

2017-09-01

Noninvasive, three-dimensional (3-D), full-field surface deformation measurements of the human body are important for biomedical investigations. We proposed a 3-D noninvasive, full-field body sensor based on stereo digital image correlation (stereo-DIC) for surface deformation monitoring of the human body in vivo. First, by applying an improved water-transfer printing (WTP) technique to transfer optimized speckle patterns onto the skin, the body sensor was conveniently and harmlessly fabricated directly onto the human body. Then, stereo-DIC was used to achieve 3-D noncontact and noninvasive surface deformation measurements. The accuracy and efficiency of the proposed body sensor were verified and discussed by considering different complexions. Moreover, the fabrication of speckle patterns on human skin, which has always been considered a challenging problem, was shown to be feasible, effective, and harmless as a result of the improved WTP technique. An application of the proposed stereo-DIC-based body sensor was demonstrated by measuring the pulse wave velocity of human carotid artery. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

The two-body problem of a pseudo-rigid body and a rigid sphere

DEFF Research Database (Denmark)

Kristiansen, Kristian Uldall; Vereshchagin, M.; Gózdziewski, K.

2012-01-01

n this paper we consider the two-body problem of a spherical pseudo-rigid body and a rigid sphere. Due to the rotational and "re-labelling" symmetries, the system is shown to possess conservation of angular momentum and circulation. We follow a reduction procedure similar to that undertaken...... in the study of the two-body problem of a rigid body and a sphere so that the computed reduced non-canonical Hamiltonian takes a similar form. We then consider relative equilibria and show that the notions of locally central and planar equilibria coincide. Finally, we show that Riemann's theorem on pseudo......-rigid bodies has an extension to this system for planar relative equilibria....

Three-body forces in p-shell nuclei

International Nuclear Information System (INIS)

Hees, A.G.M. van; Booten, J.G.L.; Glaudemans, P.W.M.

1990-01-01

Within the (0 + 1)ℎω shell-model space for p-shell nuclei we found that a schematic three-body interaction in addition to a translationally invariant two-body interaction leads to a strongly improved description of energy levels. The present three-body interaction is related to the Δ-isobar intermediate-state model of the two-pion exchange three-nucleon interaction. (orig.)

Ferritin and body mass index predict cardiac dysfunction in female adolescents with anorexia of the restrictive type.

Science.gov (United States)

Docx, Martine K F; Weyler, Joost; Simons, Annik; Ramet, José; Mertens, Luc

2015-08-01

Decreased left ventricular mass index in anorexia nervosa is amply reported. The aim of this study is to identify non-burdensome predictors of reduced left yentricular mass/height (cLVM) in a cohort of adolescent restrictive anorexic girls. This is a retrospective study of all anorexic girls of the restrictive type referred to our tertiary eating disorder unit between September 2002 and December 2012, for somatic assessment of weig ht loss. All subjects fulfilled DMS-IV criteria, without a family history of cardiac or cardiovascular diseases. In all, 283 restrictive anorexic girls (age: 14.63 +/- 1.65 y; body mass index: 15.72 +/- 1.81 kg/m2) were included. Ferritin and body mass index were independent, statistically significant predictors of the corrected left ventricular mass (P anorexia nervosa of the restrictive type. Two factors predicted decreased cLVM in our population: ferritin and BMI.

Studies of the nuclear three-body system with three dimensional Faddeev calculations

Science.gov (United States)

Liu, Hang

A three-body system consists of either a bound state of three particles with definite binding energy or a beam of single particles scattered from a target, where two of the particles are bound. Of the particles are nucleons, the interactions between them are strong and short ranged. A theoretical framework for studying the dynamics of a nuclear three-body system is the Faddeev scheme. In this work the equation for three-body scattering and the bound state are formulated in momentum space, and directly solved in terms of vector variables. For three identical bosons the Faddeev equation for scattering is a three- dimensional inhomogeneous integral equation in five variables, and is solved by Padé summation. The equation for the bound state is a homogeneous one in three variables, and is solved by a Lanczos' type method. The corresponding algorithms are presented, and their numerical feasibility is demonstrated. Elastic as well as inelastic scattering processes in the intermediate energy regime up to 1 GeV incident energy are studied for the first within a Faddeev scheme. The two-body force employed is of Malfliet-Tjon type. Specific emphasis is placed on studying the convergence of the multiple scattering series given by the Faddeev equations. For the bound state, a three-body force of Fujita- Miyazawa type is incorporated in addition to the two-body force. The effects of this three-body force on the bound state properties are investigated.

The scattering matrix element of the three body reactive collision

International Nuclear Information System (INIS)

Morsy, M.W.; Hilal, A.A.; El-Sabagh, M.A.

1980-08-01

The optical model approximation has been applied to a previously derived set of coupled equations representing the dynamics of the three-body reactive scattering. The Schroedinger equation obtained describing the scattering problem has then been solved by inserting the effective mass approximation. The asymptotic requirements for both the entrance and exit channels, respectively, have been supplied to give the scattering matrix element of the reactive collision. (author)

Morse index for figure-eight choreographies of the planar equal mass three-body problem

Science.gov (United States)

Fukuda, Hiroshi; Fujiwara, Toshiaki; Ozaki, Hiroshi

2018-04-01

We report on numerical calculations of the Morse index for figure-eight choreographic solutions to a system of three identical bodies in a plane interacting through the homogeneous potential, -1/r a , or through the Lennard-Jones-type (LJ) potential, 1/r12 - 1/r6 , where r is a distance between the bodies. The Morse index is a number of independent variational functions giving negative second variation S (2) of action functional S. We calculated three kinds of Morse indices, N, N c and N e, in the domain of the periodic, the choreographic and the figure-eight choreographic function, respectively. For the homogeneous system, we obtain N  =  4 for 0 ≤slant a index for the solution tending to the figure-eight solution of the a  =  6 homogeneous system for the period T \\to ∞ . We obtain N, N c and N e as monotonically increasing functions of T from T \\to ∞ , which start with N=N_c=N_e=0 , jump at the smallest T by 1, and reach N  =  12, N_c=4 , and N_e=1 for T \\to ∞ in the other branch.

Use of frozen stress in extracting stress intensity factor distributions in three dimensional cracked body problems

Science.gov (United States)

Smith, C. W.

1992-01-01

The adaptation of the frozen stress photoelastic method to the determination of the distribution of stress intensity factors in three dimensional problems is briefly reviewed. The method is then applied to several engineering problems of practical significance.

Fokker-type dynamics with three-body correlations

International Nuclear Information System (INIS)

Salas, A.; Sanchez-Ron, J.M.

1981-01-01

Dynamical systems of N point particles without internal degrees of freedom are studied. Their equations of motion are derived from a Fokker-type variational principle with n-body correlations (n = 2,3,...,N), with special emphasis on the case n = 3. The distinction between n-body correlation and n-body effective force is analyzed in detail, with the help of an example. Maximal sets of independent three-body Poincare-invariant scalars are given. An example of three-body correlation formally similar to the usual two-body long-range scalar correlation is given and discussed. (author)

The relativistic atomic many-body problem

International Nuclear Information System (INIS)

Brown, G.E.

1987-01-01

Problems connected with the infinite negative energy sea of electrons in the atomic many-body problem are discussed. It is shown that as long as one works in mean-field approximations, wave functions do not need to suffer from continuum dissociation. Various effects from virtual pairs in the wave functions are discussed. (orig.)

Long-term calorie restriction, but not endurance exercise, lowers core body temperature in humans

Science.gov (United States)

Soare, Andreea; Cangemi, Roberto; Omodei, Daniela; Holloszy, John O.; Fontana, Luigi

2011-01-01

Reduction of body temperature has been proposed to contribute to the increased lifespan in calorie restricted animals and mice overexpressing the uncoupling protein-2 in hypocretin neurons. However, nothing is known regarding the long-term effects of calorie restriction (CR) with adequate nutrition on body temperature in humans. In this study, 24-hour core body temperature was measured every minute by using ingested telemetric capsules in 24 men and women (mean age 53.7±9.4 yrs) consuming a CR diet for an average of 6 years, 24 age- and sex-matched sedentary (WD) and 24 body fat-matched exercise-trained (EX) volunteers, who were eating Western diets. The CR and EX groups were significantly leaner than the WD group. Energy intake was lower in the CR group (1769±348 kcal/d) than in the WD (2302±668 kcal/d) and EX (2798±760 kcal/d) groups (Ptemperatures were all significantly lower in the CR group than in the WD and EX groups (P≤0.01). Long-term CR with adequate nutrition in lean and weight-stable healthy humans is associated with a sustained reduction in core body temperature, similar to that found in CR rodents and monkeys. This adaptation is likely due to CR itself, rather than to leanness, and may be involved in slowing the rate of aging. PMID:21483032

Central configurations of the collinear three-body problem and singular surfaces in the mass space

Energy Technology Data Exchange (ETDEWEB)

Xie, Zhifu, E-mail: zxie@vsu.edu [Department of Mathematics and Computer Science, Virginia State University, Petersburg, VA 23806 (United States)

2011-09-12

This Letter is to provide a new approach to study the phenomena of degeneracy of the number of the collinear central configurations under geometric equivalence. A direct and simple explicit parametric expression of the singular surface H{sub 3} is constructed in the mass space (m{sub 1},m{sub 2},m{sub 3}) element of (R{sup +}){sup 3}. The construction of H{sub 3} is from an inverse respective, that is, by specifying positions for the bodies and then determining the masses that are possible to yield a central configuration. It reveals the relationship between the phenomena of degeneracy and the inverse problem of central configurations. We prove that the number of central configurations is decreased to 3!/2-1=2, m{sub 1}, m{sub 2}, and m{sub 3} are mutually distinct if m element of H{sub 3}. Moreover, we know not only the number of central configurations but also what the nonequivalent central configurations are. -- Highlights: → Provide a new method to study the degeneracy of number of CC. → Results advanced the understanding of number of central configurations. → Singular mass surface H{sub 3} is given by a direct and simple parametric expression. → The proof only requires some basic knowledge of linear algebra. → The method can be applied to some other collinear n-body problem.

Two-body and three-body correlations in Os-shell nuclei

International Nuclear Information System (INIS)

Halderson, D.W.

1974-01-01

It is well known that conventional Brueckner calculations with modern nucleon-nucleon potentials have failed to reproduce experimental saturation properties of finite nuclei. The intent was to determine whether the discrepancies are due to the methods of calculation or the nucleon-nucleon potentials. Brueckner procedures which include only two-body correlations were applied to Os-shell nuclei. Calculations were performed with and without the Hartree-Fock condition, with and without partial occupation probabilities, and with various propagators and Pauli correction techniques. Then the entire class of three-body correlations was calculated by matrix solution of the Bethe-Faddeev equations. The convergence necessary to validate this technique was achieved by constructing a set of basic functions which contain no center of mass excitations and yet are still properly antisymmetrized. The two-body calculations yielded typical Brueckner results. The nuclei were underbound or the radii were too small. However, the three-body calculations yielded reasonable radii and moderate overbinding for the Reid soft core and Hamada-Johnston potentials. Therefore, the Bethe-Faddeev formalism has been shown to be a reasonable approach to calculation of the three-body correlations in finite nuclei; and the results of []these calculations demonstrate that the underbinding and collapsed radii of two-body calculations were largely due to the uncalculated correlations. (auth)

The computationalist reformulation of the mind-body problem.

Science.gov (United States)

Marchal, Bruno

2013-09-01

Computationalism, or digital mechanism, or simply mechanism, is a hypothesis in the cognitive science according to which we can be emulated by a computer without changing our private subjective feeling. We provide a weaker form of that hypothesis, weaker than the one commonly referred to in the (vast) literature and show how to recast the mind-body problem in that setting. We show that such a mechanist hypothesis does not solve the mind-body problem per se, but does help to reduce partially the mind-body problem into another problem which admits a formulation in pure arithmetic. We will explain that once we adopt the computationalist hypothesis, which is a form of mechanist assumption, we have to derive from it how our belief in the physical laws can emerge from *only* arithmetic and classical computer science. In that sense we reduce the mind-body problem to a body problem appearance in computer science, or in arithmetic. The general shape of the possible solution of that subproblem, if it exists, is shown to be closer to "Platonist or neoplatonist theology" than to the "Aristotelian theology". In Plato's theology, the physical or observable reality is only the shadow of a vaster hidden nonphysical and nonobservable, perhaps mathematical, reality. The main point is that the derivation is constructive, and it provides the technical means to derive physics from arithmetic, and this will make the computationalist hypothesis empirically testable, and thus scientific in the Popperian analysis of science. In case computationalism is wrong, the derivation leads to a procedure for measuring "our local degree of noncomputationalism". Copyright © 2013 Elsevier Ltd. All rights reserved.

Abstract Cauchy problems three approaches

CERN Document Server

Melnikova, Irina V

2001-01-01

Although the theory of well-posed Cauchy problems is reasonably understood, ill-posed problems-involved in a numerous mathematical models in physics, engineering, and finance- can be approached in a variety of ways. Historically, there have been three major strategies for dealing with such problems: semigroup, abstract distribution, and regularization methods. Semigroup and distribution methods restore well-posedness, in a modern weak sense. Regularization methods provide approximate solutions to ill-posed problems. Although these approaches were extensively developed over the last decades by many researchers, nowhere could one find a comprehensive treatment of all three approaches.Abstract Cauchy Problems: Three Approaches provides an innovative, self-contained account of these methods and, furthermore, demonstrates and studies some of the profound connections between them. The authors discuss the application of different methods not only to the Cauchy problem that is not well-posed in the classical sense, b...

Equilibrium Solutions of the Logarithmic Hamiltonian Leapfrog for the N-body Problem

Science.gov (United States)

Minesaki, Yukitaka

2018-04-01

We prove that a second-order logarithmic Hamiltonian leapfrog for the classical general N-body problem (CGNBP) designed by Mikkola and Tanikawa and some higher-order logarithmic Hamiltonian methods based on symmetric multicompositions of the logarithmic algorithm exactly reproduce the orbits of elliptic relative equilibrium solutions in the original CGNBP. These methods are explicit symplectic methods. Before this proof, only some implicit discrete-time CGNBPs proposed by Minesaki had been analytically shown to trace the orbits of elliptic relative equilibrium solutions. The proof is therefore the first existence proof for explicit symplectic methods. Such logarithmic Hamiltonian methods with a variable time step can also precisely retain periodic orbits in the classical general three-body problem, which generic numerical methods with a constant time step cannot do.

Geometric characterization for the least Lagrangian action of n-body problems

Institute of Scientific and Technical Information of China (English)

ZHANG; Shiqing

2001-01-01

［1］Manev, G., La gravitation et l'énergie au zéro, Comptes Rendus, 924, 78: 259.［2］Diacu, F. N., Near-collision dynamics for particle systems with quasihomogeneous potentials, J. of Diff. Equ., 996, 28: 58.［3］Ambrosetti, A., Coti Zelati, V., Periodic Solutions of Singular Lagrangian Systems, Basel: Birkhuser, 993.［4］Arnold, V., Kozlov, V., Neishtadt, A., Dynamical Systems (iii): Mathematical Aspects of Classical and Celestial Mechanics, Berlin: Springer-Verlag, 988.［5］Chenciner, A., Desolneux, N., Minima de l'intégrale d'action et équilibres relatifs de n corps, C R Acad. Sci. Paris, serie I, 998, 326: 209.［6］Coti Zelati, V., The periodic solutions of n-body type problems, Ann IHP Anal nonlinéaire, 990, 7: 477.［7］Euler, L., De motu rectilineo trium corprum se mutuo attrahentium, Novi. Comm. Acad. Sci. Imp. Petropll, 767: 45.［8］Gordon, W., A minimizing property of Keplerian orbits, Amer. J. Math., 977, 99: 96.［9］Lagrange, J., Essai sur le problé me des trois corps, 772, Ouvres, 783, 3: 229.［10］Long, Y., Zhang, S. Q., Geometric characterization for variational minimization solutions of the 3-body problem, Chinese Science Bulletin, 999, 44(8): 653.［11］Long, Y., Zhang, S. Q., Geometric characterization for variational minimization solutions of the 3-body problem with fixed energy, J. of Diff. Equ., 2000, 60: 422.［12］Meyer, K., Hall, G., Introduction to Hamiltonian systems and the n-body problems, Berlin: Springer-Verlag,992.［13］Serra, E., Terracini, S., Collisionless periodic solutions to some three-body problems, Arch. Rational Mech. Anal., 992, 20: 305.［14］Siegle, C., Moser, J., Lectures on Celestial Mechanics, Berlin: Springer-Verlag, 97.［15］Wintner, A., Analytical Foundations of Celestial Mechanics, Princeton: Princeton University Press, 94.［16］Hardy, G., Littlewood, J., Pólya, G., Inequalities, 2nd ed., Cambridge: Combridge University Press, 952.

Short history of nuclear many-body problem

International Nuclear Information System (INIS)

Köhler, H.S.

2014-01-01

This is a very short presentation regarding developments in the theory of nuclear many-body problems, as seen and experienced by the author during the past 60 years with particular emphasis on the contributions of Gerry Brown and his research-group. Much of his work was based on Brueckner's formulation of the nuclear many-body problem. It is reviewed briefly together with the Moszkowski–Scott separation method that was an important part of his early work. The core polarisation and his work related to effective interactions in general are also addressed

Microarray analysis of subcutaneous adipose tissue from mature cows with divergent body weight gain after feed restriction and realimentation

Directory of Open Access Journals (Sweden)

H.C. Cunningham

2018-02-01

Full Text Available Body weight response to periods of feed restriction and realimentation is critical and relevant to the agricultural industry. The purpose of this study was to evaluate differentially expressed genes identified in subcutaneous adipose tissue collected from cows divergent in body weight (BW gain after feed restriction and realimentation. We compared adipose samples from cows with greater gain based on average daily gain (ADG during realimentation with samples from cows with lesser gain. Specifically, there were four comparisons including two comparing the high and low gain animals across each feeding period (feed restriction and realimentation and two that compared differences in feed restriction and realimentation across high or low gain classifications. Using microarray analysis, we provide a set of differentially expressed genes identified between the high and low gain at both periods of nutrient restriction and realimentation. These data identify multiple differentially expressed genes between these two phenotypes across both nutritional environments. Keywords: Beef cows, Subcutaneous fat, Transcriptome

Optimizing Restriction Site Placement for Synthetic Genomes

Science.gov (United States)

Montes, Pablo; Memelli, Heraldo; Ward, Charles; Kim, Joondong; Mitchell, Joseph S. B.; Skiena, Steven

Restriction enzymes are the workhorses of molecular biology. We introduce a new problem that arises in the course of our project to design virus variants to serve as potential vaccines: we wish to modify virus-length genomes to introduce large numbers of unique restriction enzyme recognition sites while preserving wild-type function by substitution of synonymous codons. We show that the resulting problem is NP-Complete, give an exponential-time algorithm, and propose effective heuristics, which we show give excellent results for five sample viral genomes. Our resulting modified genomes have several times more unique restriction sites and reduce the maximum gap between adjacent sites by three to nine-fold.

Nucleon many-body problem using quantum-mechanical few-body technique

International Nuclear Information System (INIS)

Horiuchi, Wataru

2016-01-01

A nucleus is treated as a quantum-mechanical many-body system consisting of protons and neutrons that interact with each other by nuclear force. This paper explains the variational calculation using the correlated basis function as a powerful technique for obtaining the precise solution of Schroedinger equation of many-body, and tries to understand the nucleon many-body system from the viewpoint of a few-body through the application cases of various nuclear systems. It describes the important correlation that characterizes the nucleon many-body system such as the mean field, cluster, and tensor of bound state, and shows that non-bound state is also describable. Since such precise theory is mantic, it is essential for explaining the nature of unknown unstable nuclei, and for determining the nuclear reaction rate under the environment of the stars difficult for experiment. The method is general and flexible, and can be applied to various quantum-mechanical many-body problems. For example, the multi-body calculation of atoms and molecules, hypernuclei, and hadron spectroscopy can be carried out only by changing the potential and particles. (A.O.)

Body-mass, survival, and pairing consequences of winter-diet restriction in wood ducks

Science.gov (United States)

Demarest, D.W.; Kaminski, R.M.; Brennan, L.A.; Boyle, C.R.

1997-01-01

We conducted feeding experiments with captive, wild-strain wood ducks (Aix sponsa) during winters 1990-91 and 1991-92 to test effects of increasing levels of food restriction on body mass dynamics, mortality, and pair formation. Male and female wood ducks fed restricted diets (i.e., 5, 10, 15, or 20% less food [g] than consumed on the previous day by a control group fed ad libitum) weighed less (P ??? 0.037) than birds fed ad libitum; those on 15 and 20% restricted diets weighed least. Increased mortality and decreased pair formation occurred only within the 20% restricted group (P ??? 0.049). We concluded that food restriction ranging between 15 and 20% of ad libitum intake may signify a threshold above which survival and reproduction of captive wood ducks may be impaired. Because energy costs of free living are greater than in captivity, a lower threshold may exist for wild wood ducks. Research is needed to validate the threshold theory for free-ranging wood ducks and other waterfowl, and to evaluate its potential application for conservation of winter foraging habitat. Conservation of bottomland hardwood ecosystems, which provide important foraging habitat for migrating and wintering wood ducks, should be encouraged to prevent potential negative effects on wood duck life-cycle events.

Three body dynamics and its applications to exoplanets

CERN Document Server

Musielak, Zdzislaw

2017-01-01

This brief book provides an overview of the gravitational orbital evolution of few-body systems, in particular those consisting of three bodies. The authors present the historical context that begins with the origin of the problem as defined by Newton, which was followed up by Euler, Lagrange, Laplace, and many others. Additionally, they consider the modern works from the 20th and 21st centuries that describe the development of powerful analytical methods by Poincare and others. The development of numerical tools, including modern symplectic methods, are presented as they pertain to the identification of short-term chaos and long term integrations of the orbits of many astronomical architectures such as stellar triples, planets in binaries, and single stars that host multiple exoplanets. The book includes some of the latest discoveries from the Kepler and now K2 missions, as well as applications to exoplanets discovered via the radial velocity method. Specifically, the authors give a unique perspective in rel...

Two- and three-index formulations of the minimum cost multicommodity k-splittable flow problem

DEFF Research Database (Denmark)

Gamst, Mette; Jensen, Peter Neergaard; Pisinger, David

2010-01-01

The multicommodity flow problem (MCFP) considers the efficient routing of commodities from their origins to their destinations subject to capacity restrictions and edge costs. Baier et al. [G. Baier, E. Köhler, M. Skutella, On the k-splittable flow problem, in: 10th Annual European Symposium...... of commodities has to be satisfied at the lowest possible cost. The problem has applications in transportation problems where a number of commodities must be routed, using a limited number of distinct transportation units for each commodity. Based on a three-index formulation by Truffot et al. [J. Truffot, C...... on Algorithms, 2002, 101–113] introduced the maximum flow multicommodity k-splittable flow problem (MCkFP) where each commodity may use at most k paths between its origin and its destination. This paper studies the -hard minimum cost multicommodity k-splittable flow problem (MCMCkFP) in which a given flow...

Caloric restriction in C57BL/6J mice mimics therapeutic fasting in humans

Directory of Open Access Journals (Sweden)

Denny Christine A

2006-05-01

Full Text Available Abstract Background Caloric restriction (CR has long been recognized as a dietary therapy that improves health and increases longevity. Little is known about the persistent effects of CR on plasma biomarkers (glucose, ketone bodies, and lipids following re-feeding in mice. It is also unclear how these biomarker changes in calorically restricted mice relate to those observed previously in calorically restricted humans. Results Three groups of individually housed adult female C57BL/6J (B6 mice (n = 4/group were fed a standard rodent chow diet either: (1 unrestricted (UR; (2 restricted for three weeks to reduce body weight by approximately 15–20% (R; or (3 restricted for three weeks and then re-fed unrestricted (ad libitum for an additional three weeks (R-RF. Body weight and food intake were measured throughout the study, while plasma lipids and levels of glucose and ketone bodies (β-hydroxybutyrate were measured at the termination of the study. Plasma glucose, phosphatidylcholine, cholesterol, and triglycerides were significantly lower in the R mice than in the UR mice. In contrast, plasma fatty acids and β-hydroxybutyrate were significantly higher in the R mice than in the UR mice. CR had no effect on plasma phosphatidylinositol levels. While body weight and plasma lipids of the R-RF mice returned to unrestricted levels upon re-feeding, food intake and glucose levels remained significantly lower than those prior to the initiation of CR. Conclusion CR establishes a new homeostatic state in B6 mice that persists for at least three weeks following ad libitum re-feeding. Moreover, the plasma biomarker changes observed in B6 mice during CR mimic those reported in humans on very low calorie diets or during therapeutic fasting.

Scattering Length Scaling Laws for Ultracold Three-Body Collisions

International Nuclear Information System (INIS)

D'Incao, J.P.; Esry, B.D.

2005-01-01

We present a simple and unifying picture that provides the energy and scattering length dependence for all inelastic three-body collision rates in the ultracold regime for three-body systems with short-range two-body interactions. Here, we present the scaling laws for vibrational relaxation, three-body recombination, and collision-induced dissociation for systems that support s-wave two-body collisions. These systems include three identical bosons, two identical bosons, and two identical fermions. Our approach reproduces all previous results, predicts several others, and gives the general form of the scaling laws in all cases

Dynamics of Three-Body Correlations in Quenched Unitary Bose Gases

Science.gov (United States)

Colussi, V. E.; Corson, J. P.; D'Incao, J. P.

2018-03-01

We investigate dynamical three-body correlations in the Bose gas during the earliest stages of evolution after a quench to the unitary regime. The development of few-body correlations is theoretically observed by determining the two- and three-body contacts. We find that the growth of three-body correlations is gradual compared to two-body correlations. The three-body contact oscillates coherently, and we identify this as a signature of Efimov trimers. We show that the growth of three-body correlations depends nontrivially on parameters derived from both the density and Efimov physics. These results demonstrate the violation of scaling invariance of unitary bosonic systems via the appearance of log-periodic modulation of three-body correlations.

The effects of graded levels of calorie restriction: III. Impact of short term calorie and protein restriction on mean daily body temperature and torpor use in the C57BL/6 mouse

Science.gov (United States)

Mitchell, Sharon E.; Delville, Camille; Konstantopedos, Penelope; Derous, Davina; Green, Cara L.; Chen, Luonan; Han, Jing-Dong J.; Wang, Yingchun; Promislow, Daniel E.L.; Douglas, Alex; Lusseau, David; Speakman, John R.

2015-01-01

A commonly observed response in mammals to calorie restriction (CR) is reduced body temperature (Tb). We explored how the Tb of male C57BL/6 mice responded to graded CR (10 to 40%), compared to the response to equivalent levels of protein restriction (PR) over 3 months. Under CR there was a dynamic change in daily Tb over the first 30–35 days, which stabilized thereafter until day 70 after which a further decline was noted. The time to reach stability was dependent on restriction level. Body mass negatively correlated with Tb under ad libitum feeding and positively correlated under CR. The average Tb over the last 20 days was significantly related to the levels of body fat, structural tissue, leptin and insulin-like growth factor-1. Some mice, particularly those under higher levels of CR, showed periods of daily torpor later in the restriction period. None of the changes in Tb under CR were recapitulated by equivalent levels of PR. We conclude that changes in Tb under CR are a response only to the shortfall in calorie intake. The linear relationship between average Tb and the level of restriction supports the idea that Tb changes are an integral aspect of the lifespan effect. PMID:26286956

Muscle function and body composition profile in adolescents with restrictive anorexia nervosa: Does resistance training help?

OpenAIRE

Fernández del Valle, María; Larumbe Zabala, Eneko; Morandé Lavín, Gonzalo; Pérez Ruiz, Margarita

2016-01-01

The aim of this study was to analyze the effects of short-term resistance training on the body composition profile and muscle function in a group of Anorexia Nervosa restricting type (AN-R) patients. The sample consisted of AN-R female adolescents (12.8 ± 0.6 years) allocated into the control and intervention groups (n¼18 each). Body composition and relative strength were assessed at baseline, after 8 weeks and 4 weeks following the intervention. Body mass index (BMI) increased throughout...

Generalized separable expansion method of the two-body and the three-body scattering amplitudes

International Nuclear Information System (INIS)

Oryu, S.; Ishihara, T.

1976-01-01

A systematic method is proposed for obtaining new N-rank separable amplitudes of the two-body and the three-body equations. First of all, the authors start from the Amado equation which is modified from the three-body Faddeev equation by using the two-body Yamaguchi potential for the nucleon-nucleon interaction. It is well known that the Amado equation can be integrated on the real axis because the kernel has a logarithmic cut on the real axis. However, a separable three-body form factor which is regular on the real axis except for the cut has been found. (Auth.)

The Gravitational Million-Body Problem: A Multidisciplinary Approach to Star Cluster Dynamics

International Nuclear Information System (INIS)

Tremaine, Scott

2003-01-01

, Dynamical Evolution of Globular Clusters, or that the standard reference on the observational properties of stellar systems is Binney and Merrifield's Galactic Astronomy. A minor irritation is that many concepts are discussed several times before they are defined, and the index provides no pointer to the primary discussion; thus, for example, there are ten index entries for 'phase mixing' and no indication that the fourth of these refers to the actual definition. The book is intended as a graduate textbook but more likely it will be used mainly in other contexts: by theoretical researchers, as an indispensable reference on the dynamics of gravitational N-body systems; by observational astronomers, as a readable summary of the theory of star cluster evolution; and by physicists seeking a well-written and accessible introduction to a simple problem that remains fascinating and incompletely understood after three centuries. (book review)

CHILES, Singularity Strength of Linear Elastic Bodies by Finite Elements Method

International Nuclear Information System (INIS)

Benzley, S.E.; Beisinger, Z.E.

1981-01-01

1 - Description of problem or function: CHILES is a finite element computer program that calculates the strength of singularities in linear elastic bodies. Plane stress, plane strain, and axisymmetric conditions are treated. Crack tip singularity problems are solved by this version of the code, but any type of integrable singularity may be properly modeled by modifying selected subroutines in the program. 2 - Method of solution: A generalized, quadrilateral finite element that includes a singular point at a corner node is incorporated in the code. The displacement formulation is used and inter-element compatibility is maintained so that monotone convergence is preserved. 3 - Restrictions on the complexity of the problem: CHILES allows three singular points to be modeled in the body being analyzed and each singular point may have coupled Mode I and II deformations. 1000 nodal points may be used

Extended random-phase approximation with three-body ground-state correlations

International Nuclear Information System (INIS)

Tohyama, M.; Schuck, P.

2008-01-01

An extended random-phase approximation (ERPA) which contains the effects of ground-state correlations up to a three-body level is applied to an extended Lipkin model which contains an additional particle-scattering term. Three-body correlations in the ground state are necessary to preserve the hermiticity of the Hamiltonian matrix of ERPA. Two approximate forms of ERPA which neglect the three-body correlations are also applied to investigate the importance of three-body correlations. It is found that the ground-state energy is little affected by the inclusion of the three-body correlations. On the contrary, three-body correlations for the excited states can become quite important. (orig.)

A simple coordinate space approach to three-body problems ...

Indian Academy of Sciences (India)

problems – Examples: Halo nucleus and double-λ hypernucleus ... Department of Physics, Jadavpur University, Kolkata 700 032, India. £Banaras Hindu ..... thanks the Department of Atomic Energy, India for financial support. References.

RESONANT POST-NEWTONIAN ECCENTRICITY EXCITATION IN HIERARCHICAL THREE-BODY SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

Naoz, Smadar; Kocsis, Bence; Loeb, Abraham [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Yunes, Nicolas, E-mail: snaoz@cfa.harvard.edu [Department of Physics, Montana State University, Bozeman, MT 59718 (United States)

2013-08-20

We study the secular, hierarchical three-body problem to first-order in a post-Newtonian expansion of general relativity (GR). We expand the first-order post-Newtonian Hamiltonian to leading-order in the ratio of the semi-major axis of the two orbits. In addition to the well-known terms that correspond to the GR precession of the inner and outer orbits, we find a new secular post-Newtonian interaction term that can affect the long-term evolution of the triple. We explore the parameter space for highly inclined and eccentric systems, where the Kozai-Lidov mechanism can produce large-amplitude oscillations in the eccentricities. The standard lore, i.e., that GR effects suppress eccentricity, is only consistent with the parts of phase space where the GR timescales are several orders of magnitude shorter than the secular Newtonian one. In other parts of phase space, however, post-Newtonian corrections combined with the three-body ones can excite eccentricities. In particular, for systems where the GR timescale is comparable to the secular Newtonian timescales, the three-body interactions give rise to a resonant-like eccentricity excitation. Furthermore, for triples with a comparable-mass inner binary, where the eccentric Kozai-Lidov mechanism is suppressed, post-Newtonian corrections can further increase the eccentricity and lead to orbital flips even when the timescale of the former is much longer than the timescale of the secular Kozai-Lidov quadrupole perturbations.

Gravitational waves from periodic three-body systems.

Science.gov (United States)

Dmitrašinović, V; Suvakov, Milovan; Hudomal, Ana

2014-09-05

Three bodies moving in a periodic orbit under the influence of Newtonian gravity ought to emit gravitational waves. We have calculated the gravitational radiation quadrupolar waveforms and the corresponding luminosities for the 13+11 recently discovered three-body periodic orbits in Newtonian gravity. These waves clearly allow one to distinguish between their sources: all 13+11 orbits have different waveforms and their luminosities (evaluated at the same orbit energy and body mass) vary by up to 13 orders of magnitude in the mean, and up to 20 orders of magnitude for the peak values.

Child Disinhibition, Parent Restriction, and Child Body Mass Index in Low-Income Preschool Families

Science.gov (United States)

Sparks, Martha A.; Radnitz, Cynthia L.

2013-01-01

Objective: To examine both unique and interactive effects of parent restrictive feeding and child disinhibited eating behavior on child body mass index (BMI) in low-income Latino and African American preschoolers. Methods: The sample included 229 parent-child pairs, the majority of whom were low-income and Latino (57%) or African American (25%).…

Diffusion Monte Carlo calculation of three-body systems

International Nuclear Information System (INIS)

Lu Mengjiao; Lin Qihu; Ren Zhongzhou

2012-01-01

The application of the diffusion Monte Carlo algorithm in three-body systems is studied. We develop a program and use it to calculate the property of various three-body systems. Regular Coulomb systems such as atoms, molecules, and ions are investigated. The calculation is then extended to exotic systems where electrons are replaced by muons. Some nuclei with neutron halos are also calculated as three-body systems consisting of a core and two external nucleons. Our results agree well with experiments and others' work. (authors)

Three-body forces and the trinucleons

International Nuclear Information System (INIS)

Friar, J.L.

1987-01-01

Three-body forces are discussed in the context of classical, atomic, solid-state and nuclear physics. The basic theoretical ingredients used in the construction of such forces are reviewed. Experimental evidence for three-nucleon forces and an overview of the three-nucleon bound states are presented. 53 refs., 9 figs

Quantum N-body problem with a minimal length

International Nuclear Information System (INIS)

Buisseret, Fabien

2010-01-01

The quantum N-body problem is studied in the context of nonrelativistic quantum mechanics with a one-dimensional deformed Heisenberg algebra of the form [x,p]=i(1+βp 2 ), leading to the existence of a minimal observable length √(β). For a generic pairwise interaction potential, analytical formulas are obtained that allow estimation of the ground-state energy of the N-body system by finding the ground-state energy of a corresponding two-body problem. It is first shown that in the harmonic oscillator case, the β-dependent term grows faster with increasing N than the β-independent term. Then, it is argued that such a behavior should also be observed with generic potentials and for D-dimensional systems. Consequently, quantum N-body bound states might be interesting places to look at nontrivial manifestations of a minimal length, since the more particles that are present, the more the system deviates from standard quantum-mechanical predictions.

Three-body unitarity in the finite volume

Energy Technology Data Exchange (ETDEWEB)

Mai, M. [The George Washington University, Washington, DC (United States); Doering, M. [The George Washington University, Washington, DC (United States); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2017-12-15

The physical interpretation of lattice QCD simulations, performed in a small volume, requires an extrapolation to the infinite volume. A method is proposed to perform such an extrapolation for three interacting particles at energies above threshold. For this, a recently formulated relativistic 3 → 3 amplitude based on the isobar formulation is adapted to the finite volume. The guiding principle is two- and three-body unitarity that imposes the imaginary parts of the amplitude in the infinite volume. In turn, these imaginary parts dictate the leading power-law finite-volume effects. It is demonstrated that finite-volume poles arising from the singular interaction, from the external two-body sub-amplitudes, and from the disconnected topology cancel exactly leaving only the genuine three-body eigenvalues. The corresponding quantization condition is derived for the case of three identical scalar-isoscalar particles and its numerical implementation is demonstrated. (orig.)

Three-Body Nuclear Forces from a Matrix Model

CERN Document Server

Hashimoto, Koji

2010-01-01

We compute three-body nuclear forces at short distances by using the nuclear matrix model of holographic QCD proposed in our previous paper with P. Yi. We find that the three-body forces at short distances are repulsive for (a) aligned three neutrons with averaged spins, and (b) aligned proton-proton-neutron / proton-neutron-neutron. These indicate that in dense states of neutrons such as cores of neutron stars, or in Helium-3 / tritium nucleus, the repulsive forces are larger than the ones estimated from two-body forces only.

Three-dimensional formulation of the relativistic two-body problem in terms of rapidities

International Nuclear Information System (INIS)

Amirkhanov, I.V.; Grusha, G.V.; Mir-Kasimov, R.M.

1976-01-01

The scheme, based on the three-dimensional relativistic equation of the quasi-potential type is developed. As a basic variable rapidity, canonically conjugated to the relativistic relative distance is adopted. The free Green function has a simple pole in the complex rapidity plane, ensuring the fulfillment of the elastic unitarity for real potentials. In the local potential case the corresponding partial wave equation in configurational r-representation is a differential second-order equation. The problem of boundary conditions, which is a non-trivial one in the relativistic r-space, is studied. The exact solutions of the equation in simple cases have been found

Few-body problems

CERN Document Server

Hadjimichael, E

1986-01-01

This volume consists of two review articles. E Hadjimichael's contribution, 'The Nuclear Three-Body Systems', concentrates on recent experimental and theoretical progress achieved in the field. Together with a pedagogical survey of the theoretical framework extensive discussion on the 3N system in the continuum and reactions of electromagnetic probes with 3N systems are provided. 'Four-Nucleon Transfer Reactions' by W Oelert reviews many aspects of a-particle transfer studies. A careful and balanced presentation of both theory and experiment is given. Reasonable agreement between the two is ob

The effects of exercise training in addition to energy restriction on functional capacities and body composition in obese adults during weight loss: a systematic review.

Directory of Open Access Journals (Sweden)

Clint T Miller

Full Text Available BACKGROUND: Obesity is associated with impairments of physical function, cardiovascular fitness, muscle strength and the capacity to perform activities of daily living. This review examines the specific effects of exercise training in relation to body composition and physical function demonstrated by changes in cardiovascular fitness, and muscle strength when obese adults undergo energy restriction. METHODS: Electronic databases were searched for randomised controlled trials comparing energy restriction plus exercise training to energy restriction alone. Studies published to May 2013 were included if they used multi-component methods for analysing body composition and assessed measures of fitness in obese adults. RESULTS: Fourteen RCTs met the inclusion criteria. Heterogeneity of study characteristics prevented meta-analysis. Energy restriction plus exercise training was more effective than energy restriction alone for improving cardiovascular fitness, muscle strength, and increasing fat mass loss and preserving lean body mass, depending on the type of exercise training. CONCLUSION: Adding exercise training to energy restriction for obese middle-aged and older individuals results in favourable changes to fitness and body composition. Whilst weight loss should be encouraged for obese individuals, exercise training should be included in lifestyle interventions as it offers additional benefits.

The Effects of Exercise Training in Addition to Energy Restriction on Functional Capacities and Body Composition in Obese Adults during Weight Loss: A Systematic Review

Science.gov (United States)

Miller, Clint T.; Fraser, Steve F.; Levinger, Itamar; Straznicky, Nora E.; Dixon, John B.; Reynolds, John; Selig, Steve E.

2013-01-01

Background Obesity is associated with impairments of physical function, cardiovascular fitness, muscle strength and the capacity to perform activities of daily living. This review examines the specific effects of exercise training in relation to body composition and physical function demonstrated by changes in cardiovascular fitness, and muscle strength when obese adults undergo energy restriction. Methods Electronic databases were searched for randomised controlled trials comparing energy restriction plus exercise training to energy restriction alone. Studies published to May 2013 were included if they used multi-component methods for analysing body composition and assessed measures of fitness in obese adults. Results Fourteen RCTs met the inclusion criteria. Heterogeneity of study characteristics prevented meta-analysis. Energy restriction plus exercise training was more effective than energy restriction alone for improving cardiovascular fitness, muscle strength, and increasing fat mass loss and preserving lean body mass, depending on the type of exercise training. Conclusion Adding exercise training to energy restriction for obese middle-aged and older individuals results in favourable changes to fitness and body composition. Whilst weight loss should be encouraged for obese individuals, exercise training should be included in lifestyle interventions as it offers additional benefits. PMID:24409219

Atomic Color Superfluid via Three-Body Loss

International Nuclear Information System (INIS)

Kantian, A.; Diehl, S.; Zoller, P.; Daley, A. J.; Dalmonte, M.; Hofstetter, W.

2009-01-01

Large three-body loss rates in a three-component Fermi gas confined in an optical lattice can dynamically prevent atoms from tunneling so as to occupy a lattice site with three atoms. This effective constraint not only suppresses the occurrence of actual loss events, but stabilizes BCS-pairing phases by suppressing the formation of trions. We study the effect of the constraint on the many-body physics using bosonization and density matrix renormalization group techniques, and also investigate the full dissipative dynamics including loss for the example of 6 Li.

[Three cases of an intracranial wooden foreign body].

Science.gov (United States)

Fujimoto, S; Onuma, T; Amagasa, M; Okudaira, Y

1987-07-01

Three cases of intracranial wooden foreign body are reported discussing the diagnostic and therapeutic problems. First case is a 50-year-old man. After drinking, he drove a bike and fell to the ground. On admission the wooden foreign body could not been detected in appearance. CT scan showed low density area similar to air in bilateral anterior horn of lateral ventricle. The patient was treated for traumatic pneumocephalus at first. Later, it proved that he was stabbed with a foreign body penetrating into the contralateral frontal lobe through the left nasal cavity. It was extracted by endonasal approach by otolaryngologist, fortunately without trouble. The foreign body was a branch of tree. The second case is an 18-year-old man. He was driving a car, and suffered injury. He was stabbed with a wooden stake penetrating into his left eye. Immediately, bifrontal craniotomy was performed and the stake was withdrawn carefully. Moreover bone fragments were removed. The third case is a 61-year-old man. When he cut the timber by chain saw, a piece of wood hit and stabbed his right eye directly. Immediately right front temporal craniotomy was performed. The piece of wood was withdrawn from the right eye, and pieces of glass, wood and bone fragments were evacuated. It is difficult to confirm intracranial foreign body accurately by means of only plain skull film and usual CT scans. It is necessary to utilize various function of CT scanner. For example, it is useful to know CT values or select measure mode with window width and level or make reconstruction image to sagittal or coronal section, and so on.(ABSTRACT TRUNCATED AT 250 WORDS)

Microarray analysis of subcutaneous adipose tissue from mature cows with divergent body weight gain after feed restriction and realimentation

Science.gov (United States)

Body weight response to periods of feed restriction and realimentation is critical and relevant to the agricultural industry. The purpose of this study was to evaluate differentially expressed genes identified in subcutaneous adipose tissue collected from cows divergent in body weight (BW) gain afte...

An existence proof of a symmetric periodic orbit in the octahedral six-body problem

OpenAIRE

Cavalcanti, Anete Soares

2016-01-01

We present a proof of the existence of a periodic orbit for the Newtonian six-body problem with equal masses. This orbit has three double collisions each period and no multiple collisions. Our proof is based on the minimization of the Lagrangian action functional on a well chosen class of symmetric loops.

Covariant equations for the three-body bound state

International Nuclear Information System (INIS)

Stadler, A.; Gross, F.; Frank, M.

1997-01-01

The covariant spectator (or Gross) equations for the bound state of three identical spin 1/2 particles, in which two of the three interacting particles are always on shell, are developed and reduced to a form suitable for numerical solution. The equations are first written in operator form and compared to the Bethe-Salpeter equation, then expanded into plane wave momentum states, and finally expanded into partial waves using the three-body helicity formalism first introduced by Wick. In order to solve the equations, the two-body scattering amplitudes must be boosted from the overall three-body rest frame to their individual two-body rest frames, and all effects which arise from these boosts, including Wigner rotations and p-spin decomposition of the shell-particle, are treated exactly. In their final form, the equations reduce to a coupled set of Faddeev-like double integral equations with additional channels arising from the negative p-spin states of the off-shell particle

Observation of the Borromean Three-Body Förster Resonances for Three Interacting Rb Rydberg Atoms.

Science.gov (United States)

Tretyakov, D B; Beterov, I I; Yakshina, E A; Entin, V M; Ryabtsev, I I; Cheinet, P; Pillet, P

2017-10-27

Three-body Förster resonances at long-range interactions of Rydberg atoms were first predicted and observed in Cs Rydberg atoms by Faoro et al. [Nat. Commun. 6, 8173 (2015)NCAOBW2041-172310.1038/ncomms9173]. In these resonances, one of the atoms carries away an energy excess preventing the two-body resonance, leading thus to a Borromean type of Förster energy transfer. But they were in fact observed as the average signal for the large number of atoms N≫1. In this Letter, we report on the first experimental observation of the three-body Förster resonances 3×nP_{3/2}(|M|)→nS_{1/2}+(n+1)S_{1/2}+nP_{3/2}(|M^{*}|) in a few Rb Rydberg atoms with n=36, 37. We have found here clear evidence that there is no signature of the three-body Förster resonance for exactly two interacting Rydberg atoms, while it is present for N=3-5 atoms. This demonstrates the assumption that three-body resonances can generalize to any Rydberg atom. As such resonance represents an effective three-body operator, it can be used to directly control the three-body interactions in quantum simulations and quantum information processing with Rydberg atoms.

The changing features of the body-mind problem.

Science.gov (United States)

Agassi, Joseph

2007-01-01

The body-mind problem invites scientific study, since mental events are repeated and repeatable and invite testable explanations. They seemed troublesome because of the classical theory of substance that failed to solve its own central problems. These are soluble with the aid of the theory of the laws of nature, particularly in its emergentist version [Bunge, M., 1980. The Body-mind Problem, Pergamon, Oxford] that invites refutable explanations [Popper, K.R., 1959. The Logic of Scientific Discovery, Hutchinson, London]. The view of mental properties as emergent is a modification of the two chief classical views, materialism and dualism. As this view invites testable explanations of events of the inner world, it is better than the quasi-behaviorist view of self-awareness as computer-style self-monitoring [Minsky, M., Laske, O., 1992. A conversation with Marvin Minsky. AI Magazine 13 (3), 31-45].

On contribution of three-body forces to Nd interaction at intermediate energies

International Nuclear Information System (INIS)

Uzikov, Yu.N.

2001-01-01

Available data on large-angle nucleon-deuteron elastic scattering Nd → dN below the pion threshold give a signal for three-body forces. There is a problem of separation of possible subtle aspects of these forces from off-shell effects in two-nucleon potentials. By considering the main mechanisms of the process Nd → dN, we show qualitatively that in the quasi-binary reaction N + d → (NN) + N with the final spin singlet NN-pair in the S-state the relative contribution of the 3N forces differs substantially from the elastic channel. It gives a new testing ground for the problem in question

The quantum n-body problem in dimension d ⩾ n – 1: ground state

Science.gov (United States)

Miller, Willard, Jr.; Turbiner, Alexander V.; Escobar-Ruiz, M. A.

2018-05-01

We employ generalized Euler coordinates for the n body system in dimensional space, which consists of the centre-of-mass vector, relative (mutual) mass-independent distances r ij and angles as remaining coordinates. We prove that the kinetic energy of the quantum n-body problem for can be written as the sum of three terms: (i) kinetic energy of centre-of-mass, (ii) the second order differential operator which depends on relative distances alone and (iii) the differential operator which annihilates any angle-independent function. The operator has a large reflection symmetry group and in variables is an algebraic operator, which can be written in terms of generators of the hidden algebra . Thus, makes sense of the Hamiltonian of a quantum Euler–Arnold top in a constant magnetic field. It is conjectured that for any n, the similarity-transformed is the Laplace–Beltrami operator plus (effective) potential; thus, it describes a -dimensional quantum particle in curved space. This was verified for . After de-quantization the similarity-transformed becomes the Hamiltonian of the classical top with variable tensor of inertia in an external potential. This approach allows a reduction of the dn-dimensional spectral problem to a -dimensional spectral problem if the eigenfunctions depend only on relative distances. We prove that the ground state function of the n body problem depends on relative distances alone.

Estimating the critical determinants of a class of three-dimensional star bodies

Directory of Open Access Journals (Sweden)

Nowak Werner Georg

2017-12-01

Full Text Available In the problem of (simultaneous Diophantine approximation in ℝ3 (in the spirit of Hurwitz’s theorem, lower bounds for the critical determinant of the special three-dimensional body K2 : (y2 + z2(x2 + y2 + z2 ≤ 1 play an important role; see [1], [6]. This article deals with estimates from below for the critical determinant ∆ (Kc of more general star bodies Kc : (y2 + z2c/2(x2 + y2 + z2 ≤ 1 ; where c is any positive constant. These are obtained by inscribing into Kc either a double cone, or an ellipsoid, or a double paraboloid, depending on the size of c.

Electron capture in proton collisions with alkali atoms as a three-body problem

International Nuclear Information System (INIS)

Avakov, G.V.; Blokhintsev, L.D.; Kadyrov, A.S.; Mukhamedzhanov, A.M.

1992-01-01

A previous paper proposed an approach to the calculation of electron transfer reactions in ion-atomic collisions based on the Faddeev three-body equations written in the Alt-Grassberger-Sandhas form. In the present work this approach is used to describe the electron capture in proton collisions with alkali atoms. The results of calculation of the total and partial cross sections for charge exchange in proton collisions with Li, Na, K and Rb atoms are presented. The calculated total cross sections are in good agreement with experiment for light target atoms. In going over to heavier targets, the theoretical total cross sections, while agreeing in form, tend to be larger than the experimental ones. The calculated partial cross sections for electron capture into the 2s state of the H atom are also in agreement with experiment. Some other partial cross sections were also calculated. (author)

Local Momenta and a Three-Body Gauge

Science.gov (United States)

Schillaci, Michael Jay

2000-06-01

Here I discuss position-dependent, phlocal momentum which depend upon the logarithmic gradient of a continuum Coulomb pair. These momenta have become increasingly important in the modeling of three-body scattering phenomena, while their precise mathematical and physical nature has remained unexplored. These momenta are analytic at all values of the radial separation, except possibly at zero, and can be used to illustrate why the reigning 3C wavefunction works so well in describing many phlight-atom ion processes. I calculate the contributions for several subsystems, and explain the schillaci/threebody/ momentum.html>asymmetric results achieved by Wiese(L.M. Wiese phet al.), PRL 25, 4982 (1997)., on the breakup of the (H_3^+) ion - a massive three-body system. I propose that the local momentum herein formulated become part of a three-body gauge constraint. When applied, a non-vanishing, position-dependent phase will modulate the resulting transition amplitude. The size of this modulation depends critically upon the system.

QED effects in high-Z atoms; three-body potentials

International Nuclear Information System (INIS)

Zygelman, B.

1983-01-01

Electromagnetic three-body potentials were first studied by Primakoff and Holstein. Later, Chamugan and Schweber rederived these potentials and pointed out that they might be important in highly relativistic systems, however, their formulation was basically nonrelativistic. Mittleman, in a series of papers, constructed configuration space equations that included three-body potentials. His derivation started from first principles i.e. QED, and the resulting three-body potentials are more general than the Primakoff-Holstein potentials. In this thesis the contribution to the binding energy of a simple high-Z ion from the three-body potentials is calculated. In addition, the nature and structure of these potentials in greater detail are studied. Some ambiguities that arise when the transition from Fock to configuration space is made are studied in detail

A New Class of Solvable Many-Body Problems

Directory of Open Access Journals (Sweden)

Francesco Calogero

2012-10-01

Full Text Available A new class of solvable N-body problems is identified. They describe N unit-mass point particles whose time-evolution, generally taking place in the complex plane, is characterized by Newtonian equations of motion ''of goldfish type'' (acceleration equal force, with specific velocity-dependent one-body and two-body forces featuring several arbitrary coupling constants. The corresponding initial-value problems are solved by finding the eigenvalues of a time-dependent N×N matrix U(t explicitly defined in terms of the initial positions and velocities of the N particles. Some of these models are asymptotically isochronous, i.e. in the remote future they become completely periodic with a period T independent of the initial data (up to exponentially vanishing corrections. Alternative formulations of these models, obtained by changing the dependent variables from the N zeros of a monic polynomial of degree N to its N coefficients, are also exhibited.

Three-body ΛNN force due to Λ-Σ coupling

International Nuclear Information System (INIS)

Myint, Khin Swe; Akaishi, Yoshinori

2003-01-01

The ΛNN three - body force due to coherent Λ - Σ Coupling effect was derived from realistic Nijmegen model D potential. Repulsive and attractive three - body ΛNN forces were reconcilably accounted. For 5 He, within one - channel description, ΛNN force is largely repulsive and its origin comes from Pauli forbidden terms. Within two - channel description, attractive Pauli allowed terms exist and resulting three - body force is always attractive. Large attractive ΛNN force effect due to coherent Λ - Σ coupling effect is predicted in neutron - rich nuclei. The attractive coherent Λ - Σ coupling effect is largely enhanced at high density neutron matter. The attractive three - body ΛNN force effect is essential dynamics of Λ - Σ coupling while the repulsive Nogami three - body effect arises from Pauli forbidden diagrams. (Y. Kazumata)

Off-energy-shell variations of two-nucleon transition matrix and three-nucleon problem

International Nuclear Information System (INIS)

Stingl, M.; Sauer, P.U.

1975-01-01

For a schematic three-nucleon problem, approximate analytic expressions are derived for the functional derivatives of measurable three-particle quantities with respect to off-shell variations of the triplet-s two-nucleon transition matrix. Those quantities include neutron-deuteron scattering lengths, trinucleon binding energies, and the 3 He charge form-factor minimum; correlations between off-shell changes in the latter two are discussed. An indication is given how results of this kind may be to decide whether or not a given set of discrepancies between calculated and experimental three-nucleon observables can be reconciled in terms of off-shell variations of a nonretarded hermitean two-nucleon interaction. The treatment is not restricted to special classes of phase-shift equivalent potentials or phase-shift preserving transformations but instead makes use of a systematic parameterization of off-shell variations in terms of symmetric rational approximants of increasing order

Three-M in Word Problem Solving

Science.gov (United States)

Hajra, Sayonita Ghosh; Kofman, Victoria

2018-01-01

We describe three activities that help undergraduates (pre-service teachers) to develop scientific vocabulary on measurable attributes and units of measurement. Measurable attributes are important features in understanding a word problem and solving the problem. These activities help students comprehend word problems better by identifying…

On the calculation of dynamic and heat loads on a three-dimensional body in a hypersonic flow

Science.gov (United States)

Bocharov, A. N.; Bityurin, V. A.; Evstigneev, N. M.; Fortov, V. E.; Golovin, N. N.; Petrovskiy, V. P.; Ryabkov, O. I.; Teplyakov, I. O.; Shustov, A. A.; Solomonov, Yu S.

2018-01-01

We consider a three-dimensional body in a hypersonic flow at zero angle of attack. Our aim is to estimate heat and aerodynamic loads on specific body elements. We are considering a previously developed code to solve coupled heat- and mass-transfer problem. The change of the surface shape is taken into account by formation of the iterative process for the wall material ablation. The solution is conducted on the multi-graphics-processing-unit (multi-GPU) cluster. Five Mach number points are considered, namely for M = 20-28. For each point we estimate body shape after surface ablation, heat loads on the surface and aerodynamic loads on the whole body and its elements. The latter is done using Gauss-type quadrature on the surface of the body. The comparison of the results for different Mach numbers is performed. We also estimate the efficiency of the Navier-Stokes code on multi-GPU and central processing unit architecture for the coupled heat and mass transfer problem.

The Quantum N-Body Problem and the Auxiliary Field Method

International Nuclear Information System (INIS)

Semay, C.; Buisseret, F.; Silvestre-Brac, B.

2011-01-01

Approximate analytical energy formulas for N-body semirelativistic Hamiltonians with one- and two-body interactions are obtained within the framework of the auxiliary field method. We first review the method in the case of nonrelativistic two-body problems. A general procedure is then given for N-body systems and applied to the case of baryons in the large-N c limit. (author)

Exact calculation of three-body contact interaction to second order

International Nuclear Information System (INIS)

Kaiser, N.

2012-01-01

For a system of fermions with a three-body contact interaction the second-order contributions to the energy per particle anti E(k f ) are calculated exactly. The three-particle scattering amplitude in the medium is derived in closed analytical form from the corresponding two-loop rescattering diagram. We compare the (genuine) second-order three-body contribution to anti E(k f )∝k f 10 with the second-order term due to the density-dependent effective two-body interaction, and find that the latter term dominates. The results of the present study are of interest for nuclear many-body calculations where chiral three-nucleon forces are treated beyond leading order via a density-dependent effective two-body interaction. (orig.)

Holographic interferometry applied to the measurement of displacements of the interior points of transparent bodies.

Science.gov (United States)

Sciammarella, C A; Gilbert, J A

1976-09-01

Utilizing the light scattering property of transparent media, holographic interferometry is applied to the measurement of displacement at the interior planes of three dimensional bodies. The use of a double beam illumination and the introduction of a fictitious displacement make it feasible to obtain information corresponding to components of displacement projected on the scattering plane. When the proposed techniques are invoked, it is possible to eliminate the use of a matching index of refraction fluid in many problems involving symmetrically loaded prismatic bodies. Scattered light holographic interferometry is limited in its use to small changes in the index of refraction and to low values of relative retardation. In spite of these restrictions, a large number of technical problems in both statics and dynamics can be solved.

BOOK REVIEW: The Gravitational Million-Body Problem: A Multidisciplinary Approach to Star Cluster Dynamics

Science.gov (United States)

Heggie, D.; Hut, P.

2003-10-01

, Dynamical Evolution of Globular Clusters, or that the standard reference on the observational properties of stellar systems is Binney and Merrifield's Galactic Astronomy. A minor irritation is that many concepts are discussed several times before they are defined, and the index provides no pointer to the primary discussion; thus, for example, there are ten index entries for 'phase mixing' and no indication that the fourth of these refers to the actual definition. The book is intended as a graduate textbook but more likely it will be used mainly in other contexts: by theoretical researchers, as an indispensable reference on the dynamics of gravitational N-body systems; by observational astronomers, as a readable summary of the theory of star cluster evolution; and by physicists seeking a well-written and accessible introduction to a simple problem that remains fascinating and incompletely understood after three centuries. Scott Tremaine

Use of Green's functions in the numerical solution of two-point boundary value problems

Science.gov (United States)

Gallaher, L. J.; Perlin, I. E.

1974-01-01

This study investigates the use of Green's functions in the numerical solution of the two-point boundary value problem. The first part deals with the role of the Green's function in solving both linear and nonlinear second order ordinary differential equations with boundary conditions and systems of such equations. The second part describes procedures for numerical construction of Green's functions and considers briefly the conditions for their existence. Finally, there is a description of some numerical experiments using nonlinear problems for which the known existence, uniqueness or convergence theorems do not apply. Examples here include some problems in finding rendezvous orbits of the restricted three body system.

Two-body quantum mechanical problem on spheres

OpenAIRE

Shchepetilov, Alexey V.

2005-01-01

The quantum mechanical two-body problem with a central interaction on the sphere ${\\bf S}^{n}$ is considered. Using recent results in representation theory an ordinary differential equation for some energy levels is found. For several interactive potentials these energy levels are calculated in explicit form.

Effects of Restricted Fructose Access on Body Weight and Blood Pressure Circadian Rhythms

Directory of Open Access Journals (Sweden)

Danielle Senador

2012-01-01

Full Text Available High-fructose diet is known to produce cardiovascular and metabolic pathologies. The objective was to determine whether the timing of high fructose (10% liquid solution intake affect the metabolic and cardiovascular outcomes. Male C57BL mice with radiotelemetric probes were divided into four groups: (1 24 h water (control; (2 24 h fructose (F24; (3 12 h fructose during the light phase (F12L; (4 12 h fructose during the dark phase (F12D. All fructose groups had higher fluid intake. Body weight was increased in mice on restricted access with no difference in total caloric intake. Fasting glycemia was higher in groups with restricted access. F24 mice showed a fructose-induced blood pressure increase during the dark period. Blood pressure circadian rhythms were absent in F12L mice. Results suggest that the timing of fructose intake is an important variable in the etiology of cardiovascular and metabolic pathologies produced by high fructose consumption.

The few-body problem - some thoughts after the 1980 International Conference

International Nuclear Information System (INIS)

Moravcsik, M.J.; Oregon Univ., Eugene

1981-01-01

Recent progress in the few-body problem, as considered at the Ninth International Conference on the Few-body Problem, Eugene, Oregon, August 1980, is discussed. It is shown that these developments help to-wards the understanding of some of the systems properties of these few-body configurations, contribute to the testing of quark theories, give evidence for the validity or violation of conservation laws, add to the present knowledge of nuclear properties, off-shell nucleon-nucleon interaction and other component laws and provide reliable predictions which may be useful in applications extrinsic to the few-body itself, such as astrophysics, space physics or chemistry. (U.K.)

Equilibria of the three-body problem with rigid dumb-bell satellite

International Nuclear Information System (INIS)

Elipe, A.; Palacios, M.; Pretka-Ziomek, H.

2008-01-01

This paper is concerned with the orbital-rotational motion of an asymmetric dumb-bell (two masses with fixed distance among them) under the attraction of a central body. For this model, we find some equilibria and give sufficient conditions for their stability

Similar solutions for viscous hypersonic flow over a slender three-fourths-power body of revolution

Science.gov (United States)

Lin, Chin-Shun

1987-01-01

For hypersonic flow with a shock wave, there is a similar solution consistent throughout the viscous and inviscid layers along a very slender three-fourths-power body of revolution The strong pressure interaction problem can then be treated by the method of similarity. Numerical calculations are performed in the viscous region with the edge pressure distribution known from the inviscid similar solutions. The compressible laminar boundary-layer equations are transformed into a system of ordinary differential equations. The resulting two-point boundary value problem is then solved by the Runge-Kutta method with a modified Newton's method for the corresponding boundary conditions. The effects of wall temperature, mass bleeding, and body transverse curvature are investigated. The induced pressure, displacement thickness, skin friction, and heat transfer due to the previously mentioned parameters are estimated and analyzed.

Caloric restriction in lean and obese strains of laboratory rat: effects on body composition, metabolism, growth and overall health

Data.gov (United States)

U.S. Environmental Protection Agency — Data related to obese and lean strains of rat commonly used in the laboratory that are calorically restricted and its effects on physiologic parameters (Body...

Origins and Consequences of Religious Restrictions: A Global Overview

Science.gov (United States)

Finke, Roger

2014-01-01

Despite the international controversies surrounding religious restrictions and freedoms, the topic has only recently received substantial research attention. Drawing on this new body of research, and multiple research projects in progress, this address explores both the origins and consequences of religious restrictions in the global arena. To understand the motives for restrictions, I propose hypotheses in three areas: the relationship or lack of relationship between institutional religion and the state, the willingness and capacity of the state to ensure freedoms, and the larger social and cultural pressures restricting freedoms, including social and political movements targeting minority religions. Turning to the consequences of religious restrictions, I explore how and why restrictions alter the religious economy (i.e., formation, supply and operation of religions) and are associated with higher levels of religious persecution, religious violence and intrastate conflict in general. Finally, I review additional areas where research is needed. PMID:25364225

Assessment of mechanical and three-body abrasive wear peculiarity ...

Indian Academy of Sciences (India)

The three-body abrasive wear characteristic of fabricated composites has been assessed under different operating conditions. For this, the three-body abrasion test is done on dry abrasion test rig (TR-50)and analysed using Taguchi's experimental design scheme and analysis of variance. The results obtained from these ...

Optimization of restricted ROC surfaces in three-class classification tasks.

Science.gov (United States)

Edwards, Darrin C; Metz, Charles E

2007-10-01

We have shown previously that an N-class ideal observer achieves the optimal receiver operating characteristic (ROC) hypersurface in a Neyman-Pearson sense. Due to the inherent complexity of evaluating observer performance even in a three-class classification task, some researchers have suggested a generally incomplete but more tractable evaluation in terms of a surface, plotting only the three "sensitivities." More generally, one can evaluate observer performance with a single sensitivity or misclassification probability as a function of two linear combinations of sensitivities or misclassification probabilities. We analyzed four such formulations including the "sensitivity" surface. In each case, we applied the Neyman-Pearson criterion to find the observer which achieves optimal performance with respect to each given set of "performance description variables" under consideration. In the unrestricted case, optimization with respect to the Neyman-Pearson criterion yields the ideal observer, as does maximization of the observer's expected utility. Moreover, during our consideration of the restricted cases, we found that the two optimization methods do not merely yield the same observer, but are in fact completely equivalent in a mathematical sense. Thus, for a wide variety of observers which maximize performance with respect to a restricted ROC surface in the Neyman-Pearson sense, that ROC surface can also be shown to provide a complete description of the observer's performance in an expected utility sense.

Three-body and four-body photodisintegrations of the 4He nuclei in the Δ region

International Nuclear Information System (INIS)

Niki, Kazuaki

1991-01-01

The differential and total cross sections were measured for the three-body (pnd) and four-body (ppnn) final states in photodisintegration of 4 He in an energy range between 125 and 445 MeV. The kinematic variables were determined in an almost complete way, using a large acceptance spectrometer together with the use of tagged photons of an energy resolution of 10 MeV. We have found that the three-body reaction 4 He(γ, pn)d makes a dominant contribution among various processes which lead to non-mesonic final states. The behavior of the 4 He(γ, pn)d cross section is well described by the quasi-deuteron model (QDM). On the other hand, the four-body breakup cross sections are not consistent with the prediction of the QDM. For these four-body reactions, photon absorption by three-nucleon clusters seems to give a dominant effect. The four-body cross sections also show a broad enhancement around 300 to 400 MeV, indicating a possible participation of the Δ to the reactions. (author)

Applications of the phase function method ideas for the investigation of the two- and three-body system properties

International Nuclear Information System (INIS)

Petrov, N.M.; Pushkash, A.M.

1985-01-01

In accordance with the main idea of the phase function method the two-body off-shell scattering amplitudes are considered as the limit of the scattering amplitude sequence corresponding to the sequence of the R-radius cut-off potentials. The explicit analytical expression for the scattering amplitudes function is obtained in the case of separable potentials, due to which the three-body problem is investigated

Three-body interactions and the Landau levels using Nikiforov ...

Indian Academy of Sciences (India)

In this article, the eigenvalues for the three-body interactions on the line and the Landau levels in the presence of topological defects have been regenerated by the Nikiforov–Uvarov (NU) method. Two exhaustive lists of such exactly solvable potentials are given. Keywords. Nikiforov–Uvarov (NU) method; three-body ...

Key to good fit: body measurement problems specific to key ...

African Journals Online (AJOL)

Key to good fit: body measurement problems specific to key dimensions. ... to explore and describe the problems that the South African Clothing Industry currently ... A postal survey was conducted among South African apparel and footwear ...

The effects of feed restriction on physical activity, body weight, physiology, haematology and immunology in female mink

DEFF Research Database (Denmark)

Damgaard, Birthe Marie; Dalgaard, Tina Sørensen; Larsen, Torben

2012-01-01

The aim of the present study was to investigate if adult mink females characterised as having a high or low residual feed intake (RFI) differed in their response to feed restriction with regard to activity, body weight loss and physiological parameters. For RFI-High, the activity was higher prior...

Impact of a moderately energy-restricted diet on energy metabolism and body composition in non-obese men

NARCIS (Netherlands)

Velthuis-te Wierik, E.J.M.; Westerterp, K.R.; Berg, H. van den

1995-01-01

Objective: Since little information is available on the capacity of the non-obese to adapt to a moderate decrease in energy intake, the effect of a 10-week moderately energy-restricted diet (ER) on energy expenditure and body composition was studied. Design: A controlled intervention study. After a

Structures of two-dimensional three-body systems

International Nuclear Information System (INIS)

Ruan, W.Y.; Liu, Y.Y.; Bao, C.G.

1996-01-01

Features of the structure of L = 0 states of a two-dimensional three-body model system have been investigated. Three types of permutation symmetry of the spatial part, namely symmetric, antisymmetric, and mixed, have been considered. A comparison has been made between the two-dimensional system and the corresponding three-dimensional one. The effect of symmetry on microscopic structures is emphasized. (author)

Muscle function and body composition profile in adolescents with restrictive anorexia nervosa: does resistance training help?

Science.gov (United States)

Fernández-del-Valle, Maria; Larumbe-Zabala, Eneko; Morande-Lavin, Gonzalo; Perez Ruiz, Margarita

2016-01-01

The aim of this study was to analyze the effects of short-term resistance training on the body composition profile and muscle function in a group of Anorexia Nervosa restricting type (AN-R) patients. The sample consisted of AN-R female adolescents (12.8 ± 0.6 years) allocated into the control and intervention groups (n = 18 each). Body composition and relative strength were assessed at baseline, after 8 weeks and 4 weeks following the intervention. Body mass index (BMI) increased throughout the study (p = 0.011). Significant skeletal muscle mass (SMM) gains were found in the intervention group (p = 0.045, d = 0.6) that correlated to the change in BMI (r = 0.51, p  0.60) with change in BMI in both the groups. Significant relative strength increases (p Anorexia Nervosa Restricting Type (AN-R) AN-R is a psychiatric disorder that has a major impact on muscle mass content and function. However, little or no attention has been paid to muscle recovery. High intensity resistance training is safe for AN-R after hospitalization and enhances the force generating capacity as well as muscle mass gains. Skeletal muscle mass content and muscular function improvements are partially maintained for a short period of time when the exercise program ceases.

Efimov resonances in atomic three-body systems

International Nuclear Information System (INIS)

Mezei, J. Zs.; Papp, Z.

2006-01-01

In a recent work [Phys. Rev. Lett. 94, 143201 (2005)], we reported an accumulation of three-body resonant states attached to n=2 and higher two-body thresholds. A more careful investigation revealed that there are resonances of the same kind above the n=1 threshold as well. This suggests that the resonances attached to the thresholds are Efimov resonances

Three-body calculation of Be double-hypernuclei

Indian Academy of Sciences (India)

Energy levels and bond energy of the double- hypernucleus are calculated by considering two- and three-cluster interactions. Interactions between constituent particles are contact interactions for reproducing the low binding energy of nuclei. The effective action is constructed to involve three-body forces. In this paper ...

Smoking restrictions on campus: changes and challenges at three Canadian universities, 1970-2010.

Science.gov (United States)

Procter-Scherdtel, Amy; Collins, Damian

2013-01-01

This article examines the restriction of smoking on university campuses in the Canadian context. Indoor smoking on campus is now completely prohibited by law, and universities are increasingly moving to restrict, or prohibit, outdoor smoking on their grounds. The research focuses on three case studies to identify changes in spatial restrictions on campus smoking over the last four decades (1970-2010), and to determine the challenges involved in establishing bans in outdoor areas of campus. The three universities were selected for their different approaches to the issue of outdoor smoking. Data collection involved semi-structured interviews with 36 key informants, conducted from September 2010 to January 2011, supplemented by documentary information. Interview data were analysed thematically. Protection against environmental tobacco smoke (ETS) on campus proceeded incrementally, via policy-making at the provincial, municipal and institutional levels. Historically, institutional bans on indoor smoking were particularly significant, but their health benefits could be limited by the presence of private property on campus. Universities continue to initiate smoking restrictions today, with respect to outdoor bans. However, respondents reported myriad challenges in developing, implementing and maintaining such bans. Five principal concerns were articulated: the need for ongoing policy communication; management of community relations as smokers are displaced from campus; enforcement to ensure that the policy has practical effect; safety concerns; and difficulties relating to campus layout. Because challenges are diverse and contextual, effective protection against outdoor ETS on campus is likely to require an ongoing commitment on the part of administrators. © 2012 Blackwell Publishing Ltd.

Location of collinear equilibrium points in the generalised ...

African Journals Online (AJOL)

user

Existence of periodic orbits of the third kind in the elliptical restricted three body problem and stability of the generating solution. Bull. Ins. Theoret. Astronomy Vol. 10, pp. 523-536. Danby, J.M.A., 1964. Stability of triangular points in the Elliptic Restricted problem of three bodies. Astronomical Journal Vol. 69, pp. 165-172.

Influence of effective three-body force on the spectroscopy of 19O

International Nuclear Information System (INIS)

Haung, W.; Song, H.; Wang, Z.; Kuo, T.T.S.

1983-01-01

The purpose of the present paper is to investigate the influence of effective three-body force on the spectroscopy of 19 O. The model space was chosen as the configuration space which consists of the j-j coupling states of three valence neutrons in the s-d shell. The effective interaction including two- and three-body forces was then derived in the framework of the folded diagram method (FDM). Besides two traditional three-body terms, there is another kind of three-body force, the folded one constructed with two two-body diagrams, in FDM. The G-matrix elements of soft core Reid force were used in the numerical calculations. In the case of lacking the G-matrix elements, we adopted the matrix elements of M-3Y force as the equivalents. The results show that the influence of the effective three-body forces on the spectrum of 19 O is not of importance, but the part coming from the folded three-body term is worth noting

Exact solution of the three-boson problem at vanishing energy

International Nuclear Information System (INIS)

Mora, Ch.; Gogolin, A.O.; Egger, R.

2011-01-01

A zero-range approach is used to model resonant two-body interactions between three identical bosons. A dimensionless phase parameterizes the three-body boundary condition while the scattering length enters the Bethe-Peierls boundary condition. The model is solved exactly at zero energy for any value of the scattering length, positive or negative. From this solution, an analytical expression for the rate of three-body recombination to the universal shallow dimer is extracted. (authors)

3He(d,p)4He reaction calculation with three-body Faddeev equations

International Nuclear Information System (INIS)

Oryu, S.; Uzu, E.; Sunahara, H.; Yamada, T.; Tabaru, G.; Hino, T.

1998-01-01

In order to investigate the 3 He-n-p system as a three-body problem, we have formulated 3 He-n and 3 H-p effective potentials using both a microscopic treatment and a phenomenological approach. In the microscopic treatment, potentials are generated by means of the resonating group method (RGM) based on the Minnesota nucleon-nucleon potential. These potentials are converted into separable form by means of the microscopic Pauli correct (MPC) method. The MPC potentials are properly formulated to avoid Pauli forbidden states. The phenomenological potentials are obtained by modifying parameters of the EST approximation to the Paris nucleon-nucleon potential, such that they fit the low-energy 3 He-n, 3 H-p, and 3 He-p phase shifts. Therefore, they describe the 3 He-n differential cross section, the polarization observables, and the energy levels of 4 He. The 3 He-n-p Faddeev equations are solved numerically. We reproduce correctly the ground state and the first excited state of 5 Li. Furthermore, the Paris-type potential is used to investigate the 3 He(d,p) 4 He reaction at a deuteron bombarding energy of 270 MeV, where the system is treated as a three-body problem. Results for the polarized and unpolarized differential cross sections demonstrate convergence of the Born series. (orig.)

Spacecraft Orbit Design in the Circular Restricted Three-Body Problem Using Higher-Dimensional Poincare Maps

Science.gov (United States)

2013-12-01

depiction of “space” is simplified (for pedagogical purposes) as a 2-D plane with a point in that planar “space” defined by its location in Cartesian...93 define a value associated with the color of each plotted dot. For pedagogical purposes, the color scale in this example is discretized to only...trajectory design in this 146 investigation, a “zoom” in color is often accompanied by a filtering based on the same color scale limits, thus

Intake of milk with added micronutrients increases the effectiveness of an energy-restricted diet to reduce body weight: a randomized controlled clinical trial in Mexican women.

Science.gov (United States)

Rosado, Jorge L; Garcia, Olga P; Ronquillo, Dolores; Hervert-Hernández, Deisy; Caamaño, Maria Del C; Martínez, Guadalupe; Gutiérrez, Jessica; García, Sandra

2011-10-01

Micronutrient deficiencies have been associated with an increase in fat deposition and body weight; thus, adding them to low-fat milk may facilitate weight loss when accompanied by an energy-restricted diet. The objective was to evaluate the effect of the intake of low-fat milk and low-fat milk with added micronutrients on anthropometrics, body composition, blood glucose levels, lipids profile, C-reactive protein, and blood pressure of women following an energy-restricted diet. A 16-week randomized, controlled intervention study. One hundred thirty-nine obese women (aged 34±6 years) from five rural communities in Querétaro, Mexico. Women followed an energy-restricted diet (-500 kcal) and received in addition one of the following treatments: 250 mL of low-fat milk (LFM) three times/day, 250 mL of low-fat milk with micronutrients (LFM+M) three times/day, or a no milk control group (CON). Weight, height, and hip and waist circumferences were measured at baseline and every 4 weeks. Body composition measured by dual-energy x-ray absorptiometry, blood pressure, and blood analysis were done at baseline and at the end of the 16 weeks. Changes in weight and body composition. One-factor analysis of variance, adjusted by age, baseline values, and community random effects. After the 16-week intervention, participants in the LFM+M group lost significantly more weight (-5.1 kg; 95% CI: -6.2 to -4.1) compared with LFM (-3.6 kg; 95% CI: -4.7 to -2.6) and CON (-3.2 kg; 95% CI: -4.3 to -2.2) group members (P=0.035). Body mass index change in the LFM+M group (-2.3; 95% CI: -2.7 to -1.8) was significantly greater than LFM group members (-1.5; 95% CI: -2.0 to -1.1) and CON group members (-1.4; 95% CI: -1.9 to -0.9) (P=0.022). Change in percent body fat among LFM+M group members (-2.7%; 95% CI: -3.2 to -2.1) was significantly higher than LFM group members (-1.8%; 95% CI: -2.3 to -1.3) and CON group members (-1.6%; 95% CI: -2.2 to -1.0) (P=0.019). Change in bone mineral content was

THE MIND BODY PROBLEM: THE HERMENEUTICS OF AFRICAN ...

African Journals Online (AJOL)

principles in explaining the mind –body problem due to deep seated criticisms from the ..... over duly by his mathematical intercourse with mere materials and this made him to found his .... Ed. (New York: McGraw Hill), 1993, p. 90. 19 Emefie ...

Three-body Coulomb breakup of 11Li in the complex scaling method

International Nuclear Information System (INIS)

Myo, Takayuki; Aoyama, Shigeyoshi; Kato, Kiyoshi; Ikeda, Kiyomi

2003-01-01

Coulomb breakup strengths of 11 Li into a three-body 9 Li+n+n system are studied in the complex scaling method. We decompose the transition strengths into the contributions from three-body resonances, two-body '' 10 Li+n'' and three-body '' 9 Li+n+n'' continuum states. In the calculated results, we cannot find the dipole resonances with a sharp decay width in 11 Li. There is a low energy enhancement in the breakup strength, which is produced by both the two- and three-body continuum states. The enhancement given by the three-body continuum states is found to have a strong connection to the halo structure of 11 Li. The calculated breakup strength distribution is compared with the experimental data from MSU, RIKEN and GSI

Coherent Destruction of Tunneling of Bosons with Effective Three-Body Interactions

International Nuclear Information System (INIS)

Niu Zhen-Xia; Yu Zi-Fa; Xue Ju-Kui

2015-01-01

The tunneling dynamics of dilute boson gases with three-body interactions in a periodically driven double wells are investigated both theoretically and numerically. In our findings, when the system is with only repulsive two-body interactions or only three-body interactions, the tunneling will be suppressed; while in the case of the coupling between two- and three-body interactions, the tunneling can be either suppressed or enhanced. Particularly, when attractive three-body interactions are twice large as repulsive two-body interactions, CDT occurs at isolated points of driving force, which is similar to the linear case. Considering different interaction, the system can experience different transformation from coherent tunneling to coherent destruction of tunneling (CDT). The quasi-energy of the system as the function of the periodically driving force shows a triangular structure, which provides a deep insight into the tunneling dynamics of the system. (paper)

Management of multifactorial idiopathic epilepsy in EL mice with caloric restriction and the ketogenic diet: role of glucose and ketone bodies

Directory of Open Access Journals (Sweden)

Mantis John G

2004-10-01

Full Text Available Abstract Background The high fat, low carbohydrate ketogenic diet (KD was developed as an alternative to fasting for seizure management. While the mechanisms by which fasting and the KD inhibit seizures remain speculative, alterations in brain energy metabolism are likely involved. We previously showed that caloric restriction (CR inhibits seizure susceptibility by reducing blood glucose in the epileptic EL mouse, a natural model for human multifactorial idiopathic epilepsy. In this study, we compared the antiepileptic and anticonvulsant efficacy of the KD with that of CR in adult EL mice with active epilepsy. EL mice that experienced at least 15 recurrent complex partial seizures were fed either a standard diet unrestricted (SD-UR or restricted (SD-R, and either a KD unrestricted (KD-UR or restricted (KD-R. All mice were fasted for 14 hrs prior to diet initiation. A new experimental design was used where each mouse in the diet-restricted groups served as its own control to achieve a 20–23% body weight reduction. Seizure susceptibility, body weights, and the levels of plasma glucose and β-hydroxybutyrate were measured once/week over a nine-week treatment period. Results Body weights and blood glucose levels remained high over the testing period in the SD-UR and the KD-UR groups, but were significantly (p Conclusions The results indicate that seizure susceptibility in EL mice is dependent on plasma glucose levels and that seizure control is more associated with the amount than with the origin of dietary calories. Also, CR underlies the antiepileptic and anticonvulsant action of the KD in EL mice. A transition from glucose to ketone bodies for energy is predicted to manage EL epileptic seizures through multiple integrated changes of inhibitory and excitatory neural systems.

FaCE: a tool for Three Body Faddeev calculations with core excitation

OpenAIRE

Thompson, I. J.; Nunes, F. M.; Danilin, B. V.

2004-01-01

FaCE is a self contained programme, with namelist input, that solves the three body Faddeev equations. It enables the inclusion of excitation of one of the three bodies, whilst the other two remain inert. It is particularly useful for obtaining the binding energies and bound state structure compositions of light exotic nuclei treated as three-body systems, given the three effective two body interactions. A large variety of forms for these interactions may be defined, and supersymmetric transf...

Relationship between sleep pattern and efficacy of calorie-restricted Mediterranean diet in overweight/obese subjects.

Science.gov (United States)

Pagliai, Giuditta; Dinu, Monica; Casini, Alessandro; Sofi, Francesco

2018-02-01

The association between the sleep pattern and the effectiveness of a calorie-restricted Mediterranean diet in people with overweight/obesity has been investigated in this study. Four hundred and three subjects were provided with a calorie-restricted Mediterranean diet and followed for 9 months. Personal information, including sleep pattern, was obtained at the baseline. Body weight and composition were measured every 3 months. Poor sleepers reported to have significantly (p sleeping 6-8 or >8 h/day had an increased probability of losing fat mass than women who reported sleeping sleep pattern is necessary to maintain body weight and optimal body composition.

The harm principle as a mid-level principle?: three problems from the context of infectious disease control.

Science.gov (United States)

Krom, André

2011-10-01

Effective infectious disease control may require states to restrict the liberty of individuals. Since preventing harm to others is almost universally accepted as a legitimate (prima facie) reason for restricting the liberty of individuals, it seems plausible to employ a mid-level harm principle in infectious disease control. Moral practices like infectious disease control support - or even require - a certain level of theory-modesty. However, employing a mid-level harm principle in infectious disease control faces at least three problems. First, it is unclear what we gain by attaining convergence on a specific formulation of the harm principle. Likely candidates for convergence, a harm principle aimed at preventing harmful conduct, supplemented by considerations of effectiveness and always choosing the least intrusive means still leave ample room for normative disagreement. Second, while mid-level principles are sometimes put forward in response to the problem of normative theories attaching different weight to moral principles, employing a mid-level harm principle completely leaves open how to determine what weight to attach to it in application. Third, there appears to be a trade-off between attaining convergence and finding a formulation of the harm principle that can justify liberty-restrictions in all situations of contagion, including interventions that are commonly allowed. These are not reasons to abandon mid-level theorizing altogether. But there is no reason to be too theory-modest in applied ethics. Morally justifying e.g. if a liberty-restriction in infectious disease control is proportional to the aim of harm-prevention, promptly requires moving beyond the mid-level harm principle. © 2011 Blackwell Publishing Ltd.

Emerging bosons with three-body interactions from spin-1 atoms in optical lattices

International Nuclear Information System (INIS)

Mazza, L.; Rizzi, M.; Cirac, J. I.; Lewenstein, M.

2010-01-01

We study two many-body systems of bosons interacting via an infinite three-body contact repulsion in a lattice: a pairs quasicondensate induced by correlated hopping and the discrete version of the Pfaffian wave function. We propose to experimentally realize systems characterized by such interaction by means of a proper spin-1 lattice Hamiltonian: spin degrees of freedom are locally mapped into occupation numbers of emerging bosons, in a fashion similar to spin-1/2 and hardcore bosons. Such a system can be realized with ultracold spin-1 atoms in a Mott insulator with a filling factor of 1. The high versatility of these setups allows us to engineer spin-hopping operators breaking the SU(2) symmetry, as needed to approximate interesting bosonic Hamiltonians with three-body hardcore constraint. For this purpose we combine bichromatic spin-independent superlattices and Raman transitions to induce a different hopping rate for each spin orientation. Finally, we illustrate how our setup could be used to experimentally realize the first setup, that is, the transition to a pairs quasicondensed phase of the emerging bosons. We also report on a route toward the realization of a discrete bosonic Pfaffian wave function and list some open problems for reaching this goal.

Restricted and disrupted sleep : Effects on autonomic function, neuroendocrine stress systems and stress responsivity

NARCIS (Netherlands)

Meerlo, Peter; Sgoifo, Andrea; Suchecki, Deborah

2008-01-01

Frequently disrupted and restricted sleep is a common problem for many people in our modern around-the-clock society. In this context, it is an important question how sleep loss affects the stress systems in our bodies since these systems enable us to deal with everyday challenges. Altered activity

Upregulation of circulating myomiR following short-term energy restriction is inversely associated with whole body protein synthesis

Science.gov (United States)

The objective of the present investigation was to determine whether energy restriction (ER) influences expression of skeletal muscle-specific microRNA (miRNA) in circulation (c-myomiR) and whether changes in c-myomiR are associated with rates of whole body protein synthesis. Sixteen older (64 +/- 2 ...

Explicit treatment of N-body correlations within a density-matrix formalism

International Nuclear Information System (INIS)

Shun-Jin, W.; Cassing, W.

1985-01-01

The nuclear many-body problem is reformulated in the density-matrix approach such that n-body correlations are separated out from the reduced density matrix rho/sub n/. A set of equations for the time evolution of the n-body correlations c/sub n/ is derived which allows for physically transparent truncations with respect to the order of correlations. In the stationary limit (c/sub n/ = 0) a restriction to two-body correlations yields a generalized Bethe-Goldstone equation a restriction to body correlations yields generalized Faddeev equations in the density-matrix formulation. Furthermore it can be shown that any truncation of the set of equations (c/sub n/ = 0, n>m) is compatible with conservation laws, a quality which in general is not fulfilled if higher order correlations are treated perturbatively

The Kantian Attempt to Solve the Mind-Body Problem. A Critical Approach

Directory of Open Access Journals (Sweden)

Pedro Jesús Teruel

2014-11-01

Full Text Available The mind-body problem is one of the perennial challenges in the history of ideas. Immanuel Kant (1724-1804 tried to solve it through an approach with several modulations –parallel to his intellectual evolution– that brought him into contact with both the later projection of the theoretical issue (the mind brain problem and its practical side (the immortality question. In this paper I face the Kantian approach to the mind-body problem from a triple perspective: descriptive, appraising and critical.

Health Behaviour and Body Mass Index Among Problem Gamblers

DEFF Research Database (Denmark)

Holst Algren, Maria; Ekholm, Ola; Davidsen, Michael

2015-01-01

Problem gambling is a serious public health issue. The objective of this study was to investigate whether past year problem gamblers differed from non-problem gamblers with regard to health behaviour and body mass index (BMI) among Danes aged 16 years or older. Data were derived from the Danish...... pattern and obesity was higher among problem gamblers than among non-problem gamblers. The associations found in this study remained significant after adjustment for sex, age, educational and cohabiting status as well as other risk factors. Our findings highlight the presence of a potential, public health...... Health and Morbidity Surveys in 2005 and 2010. Past year problem gambling was defined using the lie/bet questionnaire. Logistic regression analyses were used to examine the association between past year problem gambling and health behaviour and BMI. Problem gambling was associated with unhealthy...

Three-Body Antikaon-Nucleon Systems

Czech Academy of Sciences Publication Activity Database

Shevchenko, Nina V.

2017-01-01

Roč. 58, č. 1 (2017), č. článku UNSP 6. ISSN 0177-7963 R&D Projects: GA ČR(CZ) GA15-04301S Institutional support: RVO:61389005 Keywords : three-body * antikaon-nucleon * K p interactions Subject RIV: BE - Theoretical Physics OBOR OECD: Atom ic, molecular and chemical physics (physics of atom s and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect) Impact factor: 0.877, year: 2016

Störmer problem restricted to a spherical surface and the Euler and Lagrange tops

International Nuclear Information System (INIS)

Piña, Eduardo; Cortés, Emilio

2016-01-01

In a recent work, Cortés and Poza (2015 Eur. J. Phys. 36 055009) analysed, in full, the dynamics of a charged particle in the field of a magnetic dipole restricted to a spherical surface with the dipole at its centre. This model can be considered as the classical non-relativistic Störmer problem on a sphere. Here, we started from a Lagrangian approach: we derived the Hamilton equations of motion and observed that in this restricted case the equations can be reduced to quadratures, and they were integrated numerically. From the Hamiltonian function we found, for the polar angle, an equivalent one-dimensional system of a particle in the presence of an effective potential. In the present work we start from a change of variable to the cosine of the polar angle. In terms of this variable we obtain an equation that turns out to be the same as the one of a particle in a quartic potential. Then, we can actually solve the equations of motion for the polar angle using Jacobi elliptic functions, and for the azimuthal angle we use the same integrals which were expressed by Jacobi in terms of theta functions, both in the Euler and Lagrange tops. In this restricted Störmer problem, the student at undergraduate or graduate level will have a good example of an integrable nonlinear physical system in which, after analysis of its complex dynamics, one can obtain an analytical solution by means of some special functions of mathematical physics. Additionally, one discovers that the equations of motion of this restricted case of a charge in a magnetic dipole field have the same mathematical structure as the corresponding equations of other well known integrable classical dynamical systems. (paper)

Efimov Physics and the Three-Body Parameter within a Two-Channel Framework

DEFF Research Database (Denmark)

Sørensen, Peder Klokmose; V. Fedorov, D.; S. Jensen, A.

2012-01-01

scaling laws. We recover known results for broad Feshbach resonances with small effective range, whereas in the case of narrow resonances we find a distinct non-monotonic behavior of the threshold at which the lowest Efimov trimer merges with the three-body continuum. To address the issue of the physical...... origin of the three-body parameter we provide a physically clear model for the relation between three-body physics and typical two-body atom-atom interactions. Our results demonstrate that experimental information from narrow Feshbach resonances and/or mixed systems are of vital importance to pin down...... the relation of two- and three-body physics in atomic systems....

Three-body recombination of cold fermionic atoms

International Nuclear Information System (INIS)

Suno, H; Esry, B D; Greene, Chris H

2003-01-01

Recombination of identical, spin-polarized fermions in cold three-body collisions is investigated. We parametrize the mechanisms for recombination in terms of the 'scattering volume' V p and another length scale r 0 . Model two-body interactions were used within the framework of the adiabatic hyperspherical representation. We examine the recombination rate K 3 as a function of the collision energy E for various values of V p . Not only do we consider the dominant J Π = 1 + case, but also the next-leading order contributions from J Π = 1 - and 3 - . We discuss the behaviour near a two-body resonance and the expected universality of fermionic recombination. Comparisons with boson recombination are considered in detail

Pavlov and the mind-body problem.

Science.gov (United States)

Windholz, G

1997-01-01

I. P. Pavlov claimed that the mind-body problem would ultimately be resolved by empirical methods, rather than by rational arguments. A committed monist, Pavlov was confronted by dualism in the case of an hysterical person. Under normal conditions, her body's left side was insensitive to pain, but when she was hypnotized, there was a reversal of her sensitivity to pain, with the right side becoming insensitive. Pavlov acknowledged that the divergence between stimulation and response suggested dualism, yet condemned his disciple G.P. Zelenyĭ as well as Charles S. Sherrington, for their dualistic tendencies. Pavlov's continuous adherence to monism it attributed to the influence of popular scientific books that he read during his adolescence. The books maintained that science was based upon monism. Pavlov proposed that by introducing the concept of emotions, an hysterical person's condition could be explained within the framework of his theory of higher nervous activity, thereby obviating the need to change his paradigm.

Using Analogy to Solve a Three-Step Physics Problem

Science.gov (United States)

Lin, Shih-Yin; Singh, Chandralekha

2010-10-01

In a companion paper, we discuss students' ability to take advantage of what they learn from a solved problem and transfer their learning to solve a quiz problem that has different surface features but the same underlying physics principles. Here, we discuss students' ability to perform analogical reasoning between another pair of problems. Both the problems can be solved using the same physics principles. However, the solved problem provided was a two-step problem (which can be solved by decomposing it into two sub-problems) while the quiz problem was a three-step problem. We find that it is challenging for students to extend what they learned from a two-step problem to solve a three-step problem.

Caloric Restriction in Lean and Obese Strains of Laboratory Rat: Effects on Body Composition, Metabolism, Growth, and Overall Health

Science.gov (United States)

NEW FINDINGS: What is the central question of this study? How do lean and obese rats respond physiologically to caloric restriction? What is the main finding and its importance? Obese rats show marked benefits compared with lean animals. Reduced body fat is associated with improv...

Three-body Coulomb systems using generalized angular-momentum S states

Science.gov (United States)

Whitten, R. C.; Sims, J. S.

1974-01-01

An expansion of the three-body Coulomb potential in generalized angular-momentum eigenfunctions developed earlier by one of the authors is used to compute energy eigenvalues and eigenfunctions of bound S states of three-body Coulomb systems. The results for He, H(-), e(-)e(+)e(-), and pmu(-)p are compared with the results of other computational approaches.

Caloric restriction increases ketone bodies metabolism and preserves blood flow in aging brain.

Science.gov (United States)

Lin, Ai-Ling; Zhang, Wei; Gao, Xiaoli; Watts, Lora

2015-07-01

Caloric restriction (CR) has been shown to increase the life span and health span of a broad range of species. However, CR effects on in vivo brain functions are far from explored. In this study, we used multimetric neuroimaging methods to characterize the CR-induced changes of brain metabolic and vascular functions in aging rats. We found that old rats (24 months of age) with CR diet had reduced glucose uptake and lactate concentration, but increased ketone bodies level, compared with the age-matched and young (5 months of age) controls. The shifted metabolism was associated with preserved vascular function: old CR rats also had maintained cerebral blood flow relative to the age-matched controls. When investigating the metabolites in mitochondrial tricarboxylic acid cycle, we found that citrate and α-ketoglutarate were preserved in the old CR rats. We suggest that CR is neuroprotective; ketone bodies, cerebral blood flow, and α-ketoglutarate may play important roles in preserving brain physiology in aging. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Influence of a ketogenic diet, fish-oil, and calorie restriction on plasma metabolites and lipids in C57BL/6J mice

Science.gov (United States)

2014-01-01

Background Diet therapies including calorie restriction, ketogenic diets, and fish-oil supplementation have been used to improve health and to treat a variety of neurological and non-neurological diseases. Methods We investigated the effects of three diets on circulating plasma metabolites (glucose and β-hydroxybutyrate), hormones (insulin and adiponectin), and lipids over a 32-day period in C57BL/6J mice. The diets evaluated included a standard rodent diet (SD), a ketogenic diet (KD), and a standard rodent diet supplemented with fish-oil (FO). Each diet was administered in either unrestricted (UR) or restricted (R) amounts to reduce body weight by 20%. Results The KD-UR increased body weight and glucose levels and promoted a hyperlipidemic profile, whereas the FO-UR decreased body weight and glucose levels and promoted a normolipidemic profile, compared to the SD-UR. When administered in restricted amounts, all three diets produced a similar plasma metabolite profile, which included decreased glucose levels and a normolipidemic profile. Linear regression analysis showed that circulating glucose most strongly predicted body weight and triglyceride levels, whereas calorie intake moderately predicted glucose levels and strongly predicted ketone body levels. Conclusions These results suggest that biomarkers of health can be improved when diets are consumed in restricted amounts, regardless of macronutrient composition. PMID:24910707

Effect of restricted feeding under rearing on reproduction, body condition and blood metabolites of rabbit does selected for growth rate

Directory of Open Access Journals (Sweden)

C. Naturil-Alfonso

2017-12-01

Full Text Available Young rabbit females selected for growth rate can have nutritional needs which may not be met by the common practice of feed restriction during rearing in commercial rabbit production. The aim of this study was to analyse the effect of two different feeding programmes: restricted and ad libitum feeding, applied in young rabbit females for one month at the end of rearing, on reproductive performance, body condition and circulating metabolic hormones and metabolites in a rabbit line selected by growth rate in 3 consecutive reproductive cycles. Thus, twenty-four 16-week-old does were randomly assigned to a group in which the daily recommended nutrient intakes were satisfied (fed restricted: 130 g/day, n=13 or a group fed to satiety (ad libitum: 235.5 g/day, n=11 during one month. Then, all does were inseminated in 3 consecutive cycles using a 42-day reproductive cycle. Measurements of does’ body weight, perirenal fat thickness and plasma leptin, non-esterified-fatty-acids (NEFA, beta-hydroxybutyrate (BOHB and fructosamine were performed at artificial insemination (AI, parturition and weaning time in 3 consecutive cycles. Reproductive performance of does was evaluated based on fertility, litter size at parturition, prolificacy and productivity. Differences in body weight were found only in the 1st cycle, ad libitum fed females being heavier than restricted ones. Nevertheless, body weight variances disappeared in later cycles. No differences were found in perirenal fat thickness. Finally, in ad libitum fed females slight differences were found in plasma levels of NEFAs (452 vs. 258 μekv/L and 527 vs. 306 μekv/L for 1st and 2nd cycles and BOHB (0.26 vs. 0.03 mM for 2nd cycle, but disappeared in the 3rd reproductive cycle. Fertility, prolificacy and productivity was not significantly affected by the feeding programme. Nevertheless, total litter size showed to be higher in ad libitum fed females at second parturition (8.7 vs. 5.9 kits. Therefore

Three-body interactions and the elastic constants of hcp solid 4He

Science.gov (United States)

Barnes, Ashleigh L.; Hinde, Robert J.

2017-09-01

The effect of three-body interactions on the elastic properties of hexagonal close packed solid 4He is investigated using variational path integral (VPI) Monte Carlo simulations. The solid's nonzero elastic constants are calculated, at T = 0 K and for a range of molar volumes from 7.88 cm3/mol to 20.78 cm3/mol, from the bulk modulus and the three pure shear constants C0, C66, and C44. Three-body interactions are accounted for using our recently reported perturbative treatment based on the nonadditive three-body potential of Cencek et al. Previous studies have attempted to account for the effect of three-body interactions on the elastic properties of solid 4He; however, these calculations have treated zero point motions using either the Einstein or Debye approximations, which are insufficient in the molar volume range where solid 4He is characterized as a quantum solid. Our VPI calculations allow for a more accurate treatment of the zero point motions which include atomic correlation. From these calculations, we find that agreement with the experimental bulk modulus is significantly improved when three-body interactions are considered. In addition, three-body interactions result in non-negligible differences in the calculated pure shear constants and nonzero elastic constants, particularly at higher densities, where differences of up to 26.5% are observed when three-body interactions are included. We compare to the available experimental data and find that our results are generally in as good or better agreement with experiment as previous theoretical investigations.

Trends in the development of industrially assimilated renewable energy: the problem of resource restrictions

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Nizhegorodtsev, R. M.; Ratner, S. V.

2016-03-01

An analysis of the dynamics of the development of wind and solar energy and potential resource restrictions of the dissemination of these technologies of energy generation associated with intensive use of rare earth metals and some other mineral resources are presented. The technological prospects of various directions of decisions of the problem of resource restrictions, including escalating of volumes of extraction and production of necessary mineral components, creating substitutes of scarce materials and development of recycling are considered. The bottlenecks of each of the above-mentioned decisions were founded. Conclusions are drawn on the prospects of development of the Russian high-tech sectors of the economy in the context of the most probable decisions of the problem of resource restrictions of wind and solar energy. An increase in extraction and production of rare earth metals and some other materials, stimulation of domestic research and development (R&D) to create the permanent magnets of new types and new technologies of wind-powered generation, and reduction of the resource-demand and technology development of recycling the components of power equipment are the most prospective directions of progress. The innovations in these directions will be in demand on the European, Chinese, and North American markets in the near decades due to the end of the life cycle (approximately 30 years) of wind and solar energy projects started at the turn of the 20th-21st centuries (the beginning of exponential growth in plants). The private investors and relevant regional and federal government agencies can use the qualitative characteristics of the dynamics of industrially assimilated renewable energy to choose the most promising investment orientations in energy projects and selection of the most economically sound development methods of energy and related industries.

Energy Distributions from Three-Body Decaying Many-Body Resonances

International Nuclear Information System (INIS)

Alvarez-Rodriguez, R.; Jensen, A. S.; Fedorov, D. V.; Fynbo, H. O. U.; Garrido, E.

2007-01-01

We compute energy distributions of three particles emerging from decaying many-body resonances. We reproduce the measured energy distributions from decays of two archetypal states chosen as the lowest 0 + and 1 + resonances in 12 C populated in β decays. These states are dominated by sequential, through the 8 Be ground state, and direct decays, respectively. These decay mechanisms are reflected in the ''dynamic'' evolution from small, cluster or shell-model states, to large distances, where the coordinate or momentum space continuum wave functions are accurately computed

Restriction endonuclease analysis of Pasteurella multocida isolates from three California turkey premises.

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Christiansen, K H; Carpenter, T E; Snipes, K P; Hird, D W; Ghazikhanian, G Y

1992-01-01

Three California turkey premises that had repeated outbreaks of fowl cholera were studied for periods of 2 to 4 years. Using biochemical, serologic, plasmid DNA, and restriction endonuclease analyses of isolates of Pasteurella multocida from turkeys and wildlife on the premises, strains of the organism were found to be enzootic on two of the premises. On the third, a variety of strains of P. multocida were isolated from fowl cholera outbreak flocks.

Three-body forces in nuclear matter from intermediate Δ-states in three-nucleon clusters

International Nuclear Information System (INIS)

Kouki, T.; Smulter, L.E.W.; Green, A.M.

1976-10-01

The three-body force contribution in nuclear matter is treated as a three-nucleon cluster, in which one of the nucleons becomes, in an intermediate state, a Δ(1236). All exchange diagrams are calculated and found to significantly reduce the energy per particle from the direct graph. This is contrary to earlier estimates of the exchanges, using more approximate approaches. The resulting attractive contribution is rather small, -1.1 MeV at ksub(F)=1.4 fm -1 , but the roughly linear density dependence has a crucial effect on the saturation properties. The sensitivity of the results to the correlations used, and to the two-body force spin structure, is displayed. The energy per particle from clusters with three intermediate Δ's is also estimated. (author)

Coulomb two-body problem with internal structure

International Nuclear Information System (INIS)

Kuperin, Yu.A.; Makarov, K.A.; Mel'nikov, Yu.B.

1988-01-01

The methods of the theory of extensions to an enlarged Hilbert space are used to construct a model of the interaction of the external (Coulomb) and internal (quark) channels in the two-body problem. The mutual influence of the spectra of the corresponding channel Hamiltonians is studied: it leads, in particular, to a rearrangement of the spectra of hadronic atoms. An explicit representation is obtained for the S matrix, and its singularities on the energy shell are studied

Three-body correlations in the decay of $^{10}$He and $^{13}$Li

CERN Document Server

Jonson, B; Cortina-Gil, D; Simon, H; Emling, H; Nyman, G; Nilsson, T; Johansson, H T; Borge, M J G; Paschalis, S; Muenzenberg, G; Zhukov, M V; Weick, H; Pramanik, U Datta; LeBleis, T; Meister, M; Reifarth, R; Chulkov, L V; Lantz, M; Riisager, K; Mahata, K; Suemmerer, K; Langer, C; Chatillon, A; Richter, A; Kulessa, R; Palit, R; Aksyutina, Yu; Geissel, H; Aumann, T; Shulgina, N B; Prokopowicz, W; Forssen, C; Ickert, G; Fynbo, H O U; Tengblad, O; Boretzky, K

2010-01-01

The very exotic nuclear resonance systems. He-10 and Li-13, are produced in proton-knockout reactions from relativistic beams of Li-11 and Be-14. The experimentally determined energy and angular correlations between their decay products, He-8 + n + n and Li-11 + n + n, are analyzed using an expansion of decay amplitudes in a restricted set of hyperspherical harmonics. By considering only a small number of terms it is possible to extract the expansion coefficients directly from the experimental three-body correlations. This provides a model-independent way of getting information about the decay process. on the structure of the decaying nucleus and on the quantum characteristics of the binary subsystems The results show that the He-8 + n + n relative-energy spectrum can be interpreted as consisting of two resonances, an I-pi = 0(+) ground state and an excited I-pi = 2(+) state. The Li-11 + n + n relative-energy spectrum is interpreted as an I-pi = 3/2(-) ground state overlapping with excited states having a str...

Approach method of the solutions of algebraic models of the N body problem

International Nuclear Information System (INIS)

Dufour, M.

1986-09-01

We have studied a class of algebraic eigenvalue problems that generate tridiagonal matrices. The Lipkin Hamiltonian was chosen as representative. Three methods have been implemented, whose extension to more general many body problems seems possible i) Degenerate Linked Cluster Theory (LCT), which disregards special symmetries of the interaction and defines a hierarchy of approximation based on model spaces at fixed number of particle-hole excitation of the unperturbed Hamiltonian. The method works for small perturbations but does not yield a complete description. ii) A new linearization method that replaces the matrix to be diagonalized by local (tangent) approximations by harmonic matrices. This method generalizes LCT and is a posteriori reminiscent of semi-classical ones. However of is simpler, more precise and yields a complete description of spectra. iii) A global way to characterize spectra based on Gershgorine-Hadamard disks [fr

Napping reverses increased pain sensitivity due to sleep restriction.

Science.gov (United States)

Faraut, Brice; Léger, Damien; Medkour, Terkia; Dubois, Alexandre; Bayon, Virginie; Chennaoui, Mounir; Perrot, Serge

2015-01-01

To investigate pain sensitivity after sleep restriction and the restorative effect of napping. A strictly controlled randomized crossover study with continuous polysomnography monitoring was performed. Laboratory-based study. 11 healthy male volunteers. Volunteers attended two three-day sessions: "sleep restriction" alone and "sleep restriction and nap". Each session involved a baseline night of normal sleep, a night of sleep deprivation and a night of free recovery sleep. Participants were allowed to sleep only from 02:00 to 04:00 during the sleep deprivation night. During the "sleep restriction and nap" session, volunteers took two 30-minute naps, one in the morning and one in the afternoon. Quantitative sensory testing was performed with heat, cold and pressure, at 10:00 and 16:00, on three areas: the supraspinatus, lower back and thigh. After sleep restriction, quantitative sensory testing revealed differential changes in pain stimuli thresholds, but not in thermal threshold detection: lower back heat pain threshold decreased, pressure pain threshold increased in the supraspinatus area and no change was observed for the thigh. Napping restored responses to heat pain stimuli in the lower back and to pressure stimuli in the supraspinatus area. Sleep restriction induces different types of hypersensitivity to pain stimuli in different body areas, consistent with multilevel mechanisms, these changes being reversed by napping. The napping restorative effect on pain thresholds result principally from effects on pain mechanisms, since it was independent of vigilance status.

Napping reverses increased pain sensitivity due to sleep restriction.

Directory of Open Access Journals (Sweden)

Brice Faraut

Full Text Available To investigate pain sensitivity after sleep restriction and the restorative effect of napping.A strictly controlled randomized crossover study with continuous polysomnography monitoring was performed.Laboratory-based study.11 healthy male volunteers.Volunteers attended two three-day sessions: "sleep restriction" alone and "sleep restriction and nap". Each session involved a baseline night of normal sleep, a night of sleep deprivation and a night of free recovery sleep. Participants were allowed to sleep only from 02:00 to 04:00 during the sleep deprivation night. During the "sleep restriction and nap" session, volunteers took two 30-minute naps, one in the morning and one in the afternoon.Quantitative sensory testing was performed with heat, cold and pressure, at 10:00 and 16:00, on three areas: the supraspinatus, lower back and thigh. After sleep restriction, quantitative sensory testing revealed differential changes in pain stimuli thresholds, but not in thermal threshold detection: lower back heat pain threshold decreased, pressure pain threshold increased in the supraspinatus area and no change was observed for the thigh. Napping restored responses to heat pain stimuli in the lower back and to pressure stimuli in the supraspinatus area.Sleep restriction induces different types of hypersensitivity to pain stimuli in different body areas, consistent with multilevel mechanisms, these changes being reversed by napping. The napping restorative effect on pain thresholds result principally from effects on pain mechanisms, since it was independent of vigilance status.

Heuristics for the Economic Production Quantity Problem under Restrictions on Production and Maintenance Time

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Qi Xu

2016-01-01

Full Text Available This paper proposes an economic production quantity problem with the maximal production run time and minimal preventive maintenance time over a finite planning horizon. The objective is to find the efficient production and maintenance policy to minimize the total cost composed of production, maintenance, shortages, and holding costs under the restriction on the production run time and the preventive maintenance time. The production and maintenance decisions include the production and maintenance frequencies and the production run and the maintenance time. The variability and the boundedness of the production run and maintenance time make the problem difficult to solve. Two heuristic algorithms are developed using different techniques based on the optimal properties of the relaxed problem. The performance comparison between the two algorithms is illustrated by numerical examples. The numerical results show that, for the most part, there exists a heuristic algorithm which is more effective than the other.

The effects of cosmetic surgery on body image, self-esteem, and psychological problems.

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von Soest, T; Kvalem, I L; Roald, H E; Skolleborg, K C

2009-10-01

This study aims to investigate whether cosmetic surgery has an effect on an individual's body image, general self-esteem, and psychological problems. Further tests were conducted to assess whether the extent of psychological problems before surgery influenced improvements in postoperative psychological outcomes. Questionnaire data from 155 female cosmetic surgery patients from a plastic surgery clinic were obtained before and approximately 6 months after surgery. The questionnaire consisted of measures on body image, self-esteem, and psychological problems. Pre- and postoperative values were compared. Pre- and postoperative measures were also compared with the data compiled from a representative sample of 838 Norwegian women, aged 22-55, with no cosmetic surgery experience. No differences in psychological problems between the presurgery patient and comparison samples were found, whereas differences in body image and self-esteem between the sample groups were reported in an earlier publication. Analyses further revealed an improvement in body image (satisfaction with own appearance) after surgery. A significant but rather small effect on self-esteem was also found, whereas the level of psychological problems did not change after surgery. Postoperative measures of appearance satisfaction, self-esteem, and psychological problems did not differ from values derived from the comparison sample. Finally, few psychological problems before surgery predicted a greater improvement in appearance satisfaction and self-esteem after surgery. The study provides evidence of improvement in satisfaction with own appearance after cosmetic surgery, a variable that is thought to play a central role in understanding the psychology of cosmetic surgery patients. The study also points to the factors that surgeons should be aware of, particularly the role of psychological problems, which could inhibit the positive effects of cosmetic surgery.

Perceived body weight, eating and exercise problems of different groups of women.

Science.gov (United States)

Coker, Elise; Telfer, James; Abraham, Suzanne

2012-10-01

To compare prevalence of problems with body weight, eating and exercise (past or present) of female psychiatric inpatients with routine care, gynaecological and obstetric female outpatients, and eating disorder inpatients. One thousand and thirty-eight females aged 18-55 years from routine care (n=99), gynaecological (n=263) and obstetric (n=271) outpatient clinics, and eating disorder (n=223) and general psychiatric units (n=182) participated. Participants self-reported past or current problems with weight, eating and exercise using a short survey. A sub-sample of women completed the Eating and Exercise Examination (EEE) which includes the Quality of Life for Eating Disorders (QOL ED). The prevalence of self-reported problems controlling weight (52%), disordered eating and eating disorders (43%) for the psychiatric patients was significantly greater than for the routine care and gynaecological and obstetrics outpatients. The psychiatric group had a significantly higher mean body mass index (BMI) of 27.3 kg/m(2) (standard deviation (SD)=6.7) and prevalence of self-reported obesity (28%) than the other groups. Treatment of women with psychiatric problems should include assessment and concurrent attention to body weight, eating disorder and exercise problems in association with appropriate medical, psychiatric, psychological and medication treatment of their presenting disorder.

Folding model analysis of Λ binding energies and three-body ΛNN force

International Nuclear Information System (INIS)

Mian, M.; Rahman Khan, M.Z.

1988-02-01

Working within the framework of the folding model, we analyze the Λ binding energy data of light hypernuclei with effective two-body ΛN plus three-body ΛNN interaction. The two-body density for the core nucleus required for evaluating the three-body force contribution is obtained in terms of the centre of mass pair correlation. It is found that except for Λ 5 He the data are fairly well explained. The three-body force seems to account for the density dependence of the effective two-body ΛN interaction proposed earlier. (author). 13 refs, 2 tabs

Restrictive Cardiomyopathy

Science.gov (United States)

... up in the circulatory system. In time, the heart fails. What causes it? Restrictive cardiomyopathy is often caused by diseases in other parts of the body. One known cause is cardiac ... build up in the heart tissue, making the tissue stiff and thickened. Cardiac ...

Observing Maternal Restriction of Food with 3–5-Year-Old Children: Relationships with Temperament and Later Body Mass Index (BMI

Directory of Open Access Journals (Sweden)

Claire V. Farrow

2018-06-01

Full Text Available Overt parental restriction of food has previously been associated with child weight; however, most research has relied on self-reported feeding behaviour, or observations which give little opportunity to observe restriction of food. Using a novel lab-based observational technique to increase the opportunity to observe maternal feeding restriction, we explored the relationships between maternal restriction, child responses to restriction and child temperament with child body mass index (BMI Z-scores over time. Sixty-two mother child dyads were recruited to the study when their children were aged 3–5 years and were followed up 2 years later (N = 39 dyads. Families were observed during a feeding interaction in the laboratory where cookies were offered with the main meal to increase the opportunity for maternal restriction of food. Feeding observations were coded and child temperament and BMI were measured. Controlling for current child BMI Z-scores, greater maternal verbal and physical restriction of food at 3–5 years was related to higher child BMI Z-scores at 5–7 years. More emotional children were less likely to experience restriction and less likely to accept attempts to restrict their food intake. Further research should consider children’s reactions to parental feeding behaviours in greater depth and explore how feeding practices interact with child temperament in the prediction of changes in child weight.

Few-Body Problems in Experimental Nuclear Astrophysics

DEFF Research Database (Denmark)

Fynbo, H.O.U.

2013-01-01

The 3α-reaction is one of the key reactions in nuclear astrophysics. Since it is a three-body reaction direct measurement is impossible, and therefore the reaction rate must be estimated theoretically. In this contribution I will discuss uncertainties in this reaction rate both at very low...

The convergent close-coupling method for a Coulomb three-body problem

International Nuclear Information System (INIS)

Bray, I.; Stelbovics, A.T.

1994-09-01

The close-coupling method relies on the reformulation of the Schroedinger equation into an infinite set of coupled-channel equations by expanding over the complete set of target states. The difficulty in applying this approach is that the continuum channels are known to be very important in the intermediate-energy region and coupling to them must be included with little approximation. The application of the Convergent Close-Coupling (CCC) method is discussed which allows the continuum to be treated in a systematic manner via the use of square-integrable states. The CCC method utilizes an expansion of the target in a complete set of orthogonal L 2 functions which form a basis for the underlying Hilbert space. The utility of the method relies on being able to demonstrate convergence in the scattering amplitudes of interest as the basis size is increased. Numerical examples for the well known Temkin-Poet problem are used to illustrate the method. It is estimated the methods may be readily applied to full electron-atom scattering problem. 17 refs., 4 figs

Aging, adiposity, and calorie restriction.

Science.gov (United States)

Fontana, Luigi; Klein, Samuel

2007-03-07

Excessive calorie intake and subsequent obesity increases the risk of developing chronic disease and decreases life expectancy. In rodent models, calorie restriction with adequate nutrient intake decreases the risk of developing chronic disease and extends maximum life span. To evaluate the physiological and clinical implications of calorie restriction with adequate nutrient intake. Search of PubMed (1966-December 2006) using terms encompassing various aspects of calorie restriction, dietary restriction, aging, longevity, life span, adiposity, and obesity; hand search of journals that focus on obesity, geriatrics, or aging; and search of reference lists of pertinent research and review articles and books. Reviewed reports (both basic science and clinical) included epidemiologic studies, case-control studies, and randomized controlled trials, with quality of data assessed by taking into account publication in a peer-reviewed journal, number of animals or individuals studied, objectivity of measurements, and techniques used to minimize bias. It is not known whether calorie restriction extends maximum life span or life expectancy in lean humans. However, calorie restriction in adult men and women causes many of the same metabolic adaptations that occur in calorie-restricted rodents and monkeys, including decreased metabolic, hormonal, and inflammatory risk factors for diabetes, cardiovascular disease, and possibly cancer. Excessive calorie restriction causes malnutrition and has adverse clinical effects. Calorie restriction in adult men and women causes beneficial metabolic, hormonal, and functional changes, but the precise amount of calorie intake or body fat mass associated with optimal health and maximum longevity in humans is not known. In addition, it is possible that even moderate calorie restriction may be harmful in specific patient populations, such as lean persons who have minimal amounts of body fat.

Analytical equation of state with three-body forces: Application to noble gases

International Nuclear Information System (INIS)

Río, Fernando del; Díaz-Herrera, Enrique; Guzmán, Orlando; Moreno-Razo, José Antonio; Ramos, J. Eloy

2013-01-01

We developed an explicit equation of state (EOS) for small non polar molecules by means of an effective two-body potential. The average effect of three-body forces was incorporated as a perturbation, which results in rescaled values for the parameters of the two-body potential. These values replace the original ones in the EOS corresponding to the two-body interaction. We applied this procedure to the heavier noble gases and used a modified Kihara function with an effective Axilrod-Teller-Muto (ATM) term to represent the two- and three-body forces. We also performed molecular dynamics simulations with two- and three-body forces. There was good agreement between predicted, simulated, and experimental thermodynamic properties of neon, argon, krypton, and xenon, up to twice the critical density and up to five times the critical temperature. In order to achieve 1% accuracy of the pressure at liquid densities, the EOS must incorporate the effect of ATM forces. The ATM factor in the rescaled two-body energy is most important at temperatures around and lower than the critical one. Nonetheless, the rescaling of two-body diameter cannot be neglected at liquid-like densities even at high temperature. This methodology can be extended straightforwardly to deal with other two- and three-body potentials. It could also be used for other nonpolar substances where a spherical two-body potential is still a reasonable coarse-grain approximation

Effects of three-body interactions on the dynamics of entanglement in spin chains

International Nuclear Information System (INIS)

Shi Cuihua; Wu Yinzhong; Li Zhenya

2009-01-01

With the consideration of three-body interaction, dynamics of pairwise entanglement in spin chains is studied. The dependence of pairwise entanglement dynamics on the type of coupling, and distance between the spins is analyzed in a finite chain for different initial states. It is found that, for an Ising chain, three-body interactions are not in favor of preparing entanglement between the nearest neighbor spins, while three-body interactions are favorable for creating entanglement between remote spins from a separable initial state. For an isotropic Heisenberg chain, the pairwise concurrence will decrease when three-body interactions are considered both for a separable initial state and for a maximally entangled initial state, however, three-body interactions will retard the decay of the concurrence in an Ising chain when the initial state takes the maximally entangled state.

Tests of the discretized-continuum method in three-body dipole strengths

Energy Technology Data Exchange (ETDEWEB)

Pinilla, E.C., E-mail: epinilla@ulb.ac.be [Physique Nucleaire Theorique et Physique Mathematique, C.P. 229, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Baye, D., E-mail: dbaye@ulb.ac.be [Physique Quantique, C.P. 165/82, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Physique Nucleaire Theorique et Physique Mathematique, C.P. 229, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Descouvemont, P., E-mail: pdesc@ulb.ac.be [Physique Nucleaire Theorique et Physique Mathematique, C.P. 229, Universite Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Horiuchi, W., E-mail: whoriuchi@riken.jp [RIKEN Nishina Center, Wako 351-0918 (Japan); Suzuki, Y., E-mail: suzuki@nt.sc.niigata-u.ac.jp [Department of Physics, Niigata University, Niigata 950-2181 (Japan); RIKEN Nishina Center, Wako 351-0918 (Japan)

2011-08-15

We investigate the {sup 6}He dipole distribution in a three-body {alpha}+n+n model. Two approaches are used to describe the three-body 1{sup -} continuum: the discretized-continuum method, where the scattering wave functions are approximated by square-integrable functions, and the R-matrix formalism, where their asymptotic behaviour is taken into account. We show that some ambiguity exists in the pseudostate method, owing to the smoothing technique, necessary to derive continuous distributions. We show evidence for the important role of the halo structure in the E1 dipole strength. We also address the treatment of Pauli forbidden states in the three-body wave functions.

Indirect Optimization of Three-Dimensional Multiple-Impulse Moon-to-Earth Transfers

Science.gov (United States)

Shen, Hong-Xin; Casalino, Lorenzo

2014-11-01

This paper illustrates an indirect method to optimize multiple-impulse trajectories from circular lunar orbit to Earth. Optimization is performed in the circular restricted three-body problem, and the necessary optimality conditions are found through optimal control theory. In order to overcome the difficulty of initial adjoints estimation, a homotopic approach, which is based on an auxiliary optimization problem with known solution, is developed; this approach proves to be robust and efficient. Examples are presented for a range of lunar orbit orientations to assess the impact on velocity impulse requirements. Optimization results for trajectories with different number of impulses are also compared. The developed procedure can support fast and accurate evaluation of the transfer costs for Moon-to-Earth trajectories both in nominal conditions and for contingency plans.

Nuclear Astrophysics from View Point of Few-Body Problems

International Nuclear Information System (INIS)

Tumino, A.; Spitaleri, C.; Bertulani, C.; Mukhamedzhanov, A.M.

2013-01-01

Few-body systems provide very useful tools to solve different problems for nuclear astrophysics. This is the case of indirect techniques, developed to overcome some of the limits of direct measurements at astrophysical energies. Here the Coulomb dissociation, the asymptotic normalization coefficient and the Trojan Horse method are discussed. (author)

Three-body radiative heat transfer and Casimir-Lifshitz force out of thermal equilibrium for arbitrary bodies

Science.gov (United States)

Messina, Riccardo; Antezza, Mauro

2014-05-01

We study the Casimir-Lifshitz force and the radiative heat transfer in a system consisting of three bodies held at three independent temperatures and immersed in a thermal environment, the whole system being in a stationary configuration out of thermal equilibrium. The theory we develop is valid for arbitrary bodies, i.e., for any set of temperatures, dielectric, and geometrical properties, and describes each body by means of its scattering operators. For the three-body system we provide a closed-form unified expression of the radiative heat transfer and of the Casimir-Lifshitz force (both in and out of thermal equilibrium). This expression is thus first applied to the case of three planar parallel slabs. In this context we discuss the nonadditivity of the force at thermal equilibrium, as well as the equilibrium temperature of the intermediate slab as a function of its position between two external slabs having different temperatures. Finally, we consider the force acting on an atom inside a planar cavity. We show that, differently from the equilibrium configuration, the absence of thermal equilibrium admits one or more positions of minima for the atomic potential. While the corresponding atomic potential depths are very small for typical ground-state atoms, they may become particularly relevant for Rydberg atoms, becoming a promising tool to produce an atomic trap.

Three-dimensional frictionless contact between layered elastic bodies and incorporating sharp edges

Science.gov (United States)

Tordesillas, A. A.; Hill, J. M.

1991-07-01

The roller coating system used in industry to apply paint to sheet metal involves two contacting rolling cylinders, one of which is rubber covered and through which the sheet metal travels. Of particular concern in the industry is the effect of high pressures upon the flow of paint at the ends of the rollers. In an elastohydrodynamic-lubrication analysis of the paint flow, it is the corresponding “dry-contact pressure” which is of major concern. In this paper we present a numerical solution to the three-dimensional contact problem for both smooth profiled layered bodies and those which involve sharp edges but in both cases ignoring the effects of curvature. The procedure adopted is based on one previously developed by a number of authors for homogeneous bodies. An understanding of the consequences of changing the operating variables is of prime importance in an industrial scenario. The numerical scheme described here provides complete measurements of both the deformation and the contact pressure distribution for given operating variables, which are the elastic properties and dimensions of both rolls and the total applied force.

Simplified two and three dimensional HTTR benchmark problems

International Nuclear Information System (INIS)

Zhang Zhan; Rahnema, Farzad; Zhang Dingkang; Pounders, Justin M.; Ougouag, Abderrafi M.

2011-01-01

To assess the accuracy of diffusion or transport methods for reactor calculations, it is desirable to create heterogeneous benchmark problems that are typical of whole core configurations. In this paper we have created two and three dimensional numerical benchmark problems typical of high temperature gas cooled prismatic cores. Additionally, a single cell and single block benchmark problems are also included. These problems were derived from the HTTR start-up experiment. Since the primary utility of the benchmark problems is in code-to-code verification, minor details regarding geometry and material specification of the original experiment have been simplified while retaining the heterogeneity and the major physics properties of the core from a neutronics viewpoint. A six-group material (macroscopic) cross section library has been generated for the benchmark problems using the lattice depletion code HELIOS. Using this library, Monte Carlo solutions are presented for three configurations (all-rods-in, partially-controlled and all-rods-out) for both the 2D and 3D problems. These solutions include the core eigenvalues, the block (assembly) averaged fission densities, local peaking factors, the absorption densities in the burnable poison and control rods, and pin fission density distribution for selected blocks. Also included are the solutions for the single cell and single block problems.

Two-body problem for Weber-like interactions

International Nuclear Information System (INIS)

Clemente, R.A.; Assis, A.K.T.

1991-01-01

The problem of two moving bodies interacting through a Weber-like force is presented. Trajectories are obtained analytically once relativistic and quantic considerations are neglected. The main results are that in the case of limited trajectories, in general, they are not closed and in the case of open trajectories, the deflection angles are not the same for similar particles with given energies and angular momenta but opposite potentials. This last feature suggests the possibility of a direct verification of the validity of Weber's law of force for electromagnetic interactions

Analytic properties of the partial amplitudes in the three-body problem

International Nuclear Information System (INIS)

Blokhintsev, L.D.; Simonov, Yu.A.

1978-01-01

The singularities of the partial waves for a multiple scattering series of a system of three nonrelativistic particles with arbitrary masses are studied. Both on-shell and off-shell diagrams are considered for binary processes (2→2), break-up processes (2→3) and also three-particle scattering (3→3). For any diagram there are obtained: 1) simple analytic expressions for the loci of the nonpotential singularities of the partial amplitudes, i.e. for the singularities independent of the form of interaction between particles; 2) necessary and sufficient conditions of an existence of these singularities on the physical sheet; 3) a character of the singularities. A criterium is found for the kinematic possibility of a process of N subsequent pair collisions in a classical system of three point like masses with the contact interaction the maximal number Nsub(max) of these collisions is deduced

Very massive runaway stars from three-body encounters

Science.gov (United States)

Gvaramadze, Vasilii V.; Gualandris, Alessia

2011-01-01

Very massive stars preferentially reside in the cores of their parent clusters and form binary or multiple systems. We study the role of tight very massive binaries in the origin of the field population of very massive stars. We performed numerical simulations of dynamical encounters between single (massive) stars and a very massive binary with parameters similar to those of the most massive known Galactic binaries, WR 20a and NGC 3603-A1. We found that these three-body encounters could be responsible for the origin of high peculiar velocities (≥70 km s-1) observed for some very massive (≥60-70 M⊙) runaway stars in the Milky Way and the Large Magellanic Cloud (e.g. λ Cep, BD+43°3654, Sk -67°22, BI 237, 30 Dor 016), which can hardly be explained within the framework of the binary-supernova scenario. The production of high-velocity massive stars via three-body encounters is accompanied by the recoil of the binary in the opposite direction to the ejected star. We show that the relative position of the very massive binary R145 and the runaway early B-type star Sk-69°206 on the sky is consistent with the possibility that both objects were ejected from the central cluster, R136, of the star-forming region 30 Doradus via the same dynamical event - a three-body encounter.

Erratum to : Wireless three-hop networks with stealing II : exact solutions through boundary value problems

NARCIS (Netherlands)

Guillemin, F.; Knessl, C.; Leeuwaarden, van J.S.H.

2014-01-01

Contrary to what we claimed in [5], the solution to the Riemann–Hilbert problem (4) considered in [5] for some domain Dx is in general not the restriction to Dx of the solution to the modified Riemann–Hilbert problem (6) in [5]. This occurs only when Dx is a circle, which is not the case considered

A comprehensive treatment of electromagnetic interactions and the three-body spectator equations

Energy Technology Data Exchange (ETDEWEB)

Jiri Adam; Jay Van Orden

2004-10-01

We present a general derivation the three-body spectator (Gross) equations and the corresponding electromagnetic currents. As in previous paper on two-body systems, the wave equations and currents are derived from those for Bethe-Salpeter equation with the help of algebraic method using a concise matrix notation. The three-body interactions and currents introduced by the transition to the spectator approach are isolated and the matrix elements of the e.m. current are presented in detail for system of three indistinguishable particles, namely for elastic scattering and for two and three body break-up. The general expressions are reduced to the one-boson-exchange approximation to make contact with previous work. The method is general in that it does not rely on introduction of the electromagnetic interaction with the help of the minimal replacement. It would therefore work also for other external fields.

Non-homeostatic body weight regulation through a brainstem-restricted receptor for GDF15

Energy Technology Data Exchange (ETDEWEB)

Hsu, Jer-Yuan; Crawley, Suzanne; Chen, Michael; Ayupova, Dina A.; Lindhout, Darrin A.; Higbee, Jared; Kutach, Alan; Joo, William; Gao, Zhengyu; Fu, Diana; To, Carmen; Mondal, Kalyani; Li, Betty; Kekatpure, Avantika; Wang, Marilyn; Laird, Teresa; Horner, Geoffrey; Chan, Jackie; McEntee, Michele; Lopez, Manuel; Lakshminarasimhan, Damodharan; White, Andre; Wang, Sheng-Ping; Yao, Jun; Yie, Junming; Matern, Hugo; Solloway, Mark; Haldankar, Raj; Parsons, Thomas; Tang, Jie; Shen, Wenyan D.; Alice Chen, Yu; Tian, Hui; Allan, Bernard B.

2017-09-27

Under homeostatic conditions, animals use well-defined hypothalamic neural circuits to help maintain stable body weight, by integrating metabolic and hormonal signals from the periphery to balance food consumption and energy expenditure1,2. In stressed or disease conditions, however, animals use alternative neuronal pathways to adapt to the metabolic challenges of altered energy demand3. Recent studies have identified brain areas outside the hypothalamus that are activated under these ‘non-homeostatic’ conditions4,5,6, but the molecular nature of the peripheral signals and brain-localized receptors that activate these circuits remains elusive. Here we identify glial cell-derived neurotrophic factor (GDNF) receptor alpha-like (GFRAL) as a brainstem-restricted receptor for growth and differentiation factor 15 (GDF15). GDF15 regulates food intake, energy expenditure and body weight in response to metabolic and toxin-induced stresses; we show that Gfral knockout mice are hyperphagic under stressed conditions and are resistant to chemotherapy-induced anorexia and body weight loss. GDF15 activates GFRAL-expressing neurons localized exclusively in the area postrema and nucleus tractus solitarius of the mouse brainstem. It then triggers the activation of neurons localized within the parabrachial nucleus and central amygdala, which constitute part of the ‘emergency circuit’ that shapes feeding responses to stressful conditions7. GDF15 levels increase in response to tissue stress and injury, and elevated levels are associated with body weight loss in numerous chronic human diseases8,9. By isolating GFRAL as the receptor for GDF15-induced anorexia and weight loss, we identify a mechanistic basis for the non-homeostatic regulation of neural circuitry by a peripheral signal associated with tissue damage and stress. These findings provide opportunities to develop therapeutic agents for the treatment of disorders with altered energy demand.

Explicit solution to the N-body Calogero problem

Energy Technology Data Exchange (ETDEWEB)

Brink, L [Inst. of Theoretical Physics, CTH, Goeteborg (Sweden); Hansson, T H [Inst. of Theoretical Physics, Univ. Stockholm (Sweden); Vasiliev, M A [Dept. of Theoretical Physics, P.N. Lebedev Physical Inst., Moscow (Russia)

1992-07-23

We solve the N-body Calogero problem, i.e., N particles in one dimension subject to a two-body interaction of the form 1/2 {Sigma}{sub i,j} ((x{sub i}-x{sub j}){sup 2}+g/(x{sub i}-x{sub j}){sup 2}), by constructing annihilation and creation operators of the form a{sub i}{sup -+}=(1/{radical}2)(x{sub i}{+-}ip{sub i}) where p{sub i} is a modified momentum operator obeying Heisenberg-type commutation relations with x{sub i}, involving explicitly permutation operators. On the other hand, D{sub j}=ip{sub j} can be interpreted as a covariant derivative corresponding to a flat connection. The relation to fractional statistics in 1+1 dimensions and anyons in a strong magnetic field is briefly discussed. (orig.).

Potentials of the inverse scattering problem in the three-nucleon problem

International Nuclear Information System (INIS)

Pushkash, A.M.; Simenog, I.V.; Shapoval, D.V.

1993-01-01

Possibilities of using the method of the inverse scattering problem for describing simultaneously the two-nucleon and the low-energy three-nucleon data in the S-interaction approximation are examined. 20 refs., 3 figs., 1 tab

A dynamic contact problem between elasto-viscoplastic piezoelectric bodies

Directory of Open Access Journals (Sweden)

Tedjani Hadj ammar

2014-10-01

Full Text Available We consider a dynamic contact problem with adhesion between two elastic-viscoplastic piezoelectric bodies. The contact is frictionless and is described with the normal compliance condition. We derive variational formulation for the model which is in the form of a system involving the displacement field, the electric potential field and the adhesion field. We prove the existence of a unique weak solution to the problem. The proof is based on arguments of nonlinear evolution equations with monotone operators, a classical existence and uniqueness result on parabolic inequalities, differential equations and fixed point arguments.

Derivation of a configuration space Hamiltonian for heavy atoms: three body potentials

International Nuclear Information System (INIS)

Mittleman, M.H.

1981-01-01

A brief history of the difficulties associated with the derivation of a configuration space Hamiltonian is presented. One of the problems encountered is the definition of the projection operators which must occur. A variational definition is obtained and, with simplifying assumptions, the optimum projection operators are those which project onto Hartree-Fock orbitals. This puts many previously performed numerical calculations on a firm footing. The form of the two body interactions is discussed in the context of the gauge freedom. The Coulomb gauge is the favored one but it is pointed out that it has never been proven to be the best one. Finally a form for the relativistic three election potential is given and the possibility of its observation is discussed

New integrable problems in a rigid body dynamics with cubic integral in velocities

Science.gov (United States)

Elmandouh, A. A.

2018-03-01

We introduce a new family of the 2D integrable mechanical system possessing an additional integral of the third degree in velocities. This system contains 20 arbitrary parameters. We also clarify that the majority of the previous systems with a cubic integral can be reconstructed from it as a special version for certain values of those parameters. The applications of this system are extended to include the problem of motion of a particle and rigid body about its fixed point. We announce new integrable problems describing the motion of a particle in the plane, pseudosphere, and surfaces of variable curvature. We also present a new integrable problem in a rigid body dynamics and this problem generalizes some of the previous results for Sokolov-Tsiganov, Yehia, Stretensky, and Goriachev.

Transformations of the perturbed two-body problem to unperturbed harmonic oscillators

Energy Technology Data Exchange (ETDEWEB)

Szebehely, V; Bond, V

1983-05-01

Singular, nonlinear, and Liapunov unstable equations are made regular and linear through transformations that change the perturbed planar problem of two bodies into unperturbed and undamped harmonic oscillators with constant coefficients, so that the stable solution may be immediately written in terms of the new variables. The use of arbitrary and special functions for the transformations allows the systematic discussion of previously introduced and novel anomalies. For the case of the unperturbed two-body problem, it is proved that if transformations are power functions of the radial variable, only the eccentric and the true anomalies (with the corresponding transformations of the radial variable) will result in harmonic oscillators. The present method significantly reduces computation requirements in autonomous space operations. 11 references.

Body frames and frame singularities for three-atom systems

International Nuclear Information System (INIS)

Littlejohn, R.G.; Mitchell, K.A.; Aquilanti, V.; Cavalli, S.

1998-01-01

The subject of body frames and their singularities for three-particle systems is important not only for large-amplitude rovibrational coupling in molecular spectroscopy, but also for reactive scattering calculations. This paper presents a geometrical analysis of the meaning of body frame conventions and their singularities in three-particle systems. Special attention is devoted to the principal axis frame, a certain version of the Eckart frame, and the topological inevitability of frame singularities. The emphasis is on a geometrical picture, which is intended as a preliminary study for the more difficult case of four-particle systems, where one must work in higher-dimensional spaces. The analysis makes extensive use of kinematic rotations. copyright 1998 The American Physical Society

three solutions for a semilinear elliptic boundary value problem

Indian Academy of Sciences (India)

69

Keywords: The Laplacian operator, elliptic problem, Nehari man- ifold, three critical points, weak solution. 1. Introduction. Let Ω be a smooth bounded domain in RN , N ≥ 3 . In this work, we show the existence of at least three solutions for the semilinear elliptic boundary- value problem: (Pλ).. −∆u = f(x)|u(x)|p−2u(x) + ...

Dancers' Body Esteem, Fitness Esteem, and Self-Esteem in Three Contexts

Science.gov (United States)

Van Zelst, Laura; Clabaugh, Alison; Morling, Beth

2004-01-01

Sixty-two college-aged, ballet and modern dancers evaluated their bodies and themselves in different dance and non-dance settings. In a self-report survey design, dancers' body esteem, fitness esteem, and self-esteem (an overall self-evaluation) were measured in three different contexts. Dancers rated their body esteem, fitness esteem, and…

Measurements of Charmless Three-Body and Quasi-Two-Body B Decays

Energy Technology Data Exchange (ETDEWEB)

Barrera, Barbara

2000-08-28

The authors present preliminary results of a search for several exclusive charmless hadronic B decays from electron-positron annihilation data collected by the BaBar detector near the Upsilon(4S) resonance. These include three-body decay modes with final states h{+-}h{sup minus-plus}h{+-} and h{+-}h{sup minus-plus}pi{sup 0}, and quasi-two-body decay modes with final states X{sup 0}h and X{sup 0}K{sub S}{sup 0}, where h = pi or K and X{sup 0} = eta-prime or omega. They find beta(B{sup 0} --> rho{sup minus-plus}pi{sup {+-}}) = (49{+-}13{sub {minus}5}{sup +6}) x 10{sup {minus}6} and beta(B{sup +} --> eta-prime-K{sup +}) = (62{+-}18{+-}8) x 10{sup {minus}6} and present upper limits for right other decays.

Compensatory mechanisms activated with intermittent energy restriction

DEFF Research Database (Denmark)

Coutinho, Sílvia Ribeiro; Halset, Eline Holli; Gåsbakk, Sigrid

2018-01-01

Background & aims: Strong compensatory responses, with reduced resting metabolic rate (RMR), increased exercise efficiency (ExEff) and appetite, are activated when weight loss (WL) is achieved with continuous energy restriction (CER), which try to restore energy balance. Intermittent energy...... restriction (IER), where short spells of energy restriction are interspaced by periods of habitual energy intake, may offer some protection in minimizing those responses. We aimed to compare the effect of IER versus CER on body composition and the compensatory responses induced by WL. Methods: 35 adults (age......: 39 ± 9 y) with obesity (BMI: 36 ± 4 kg/m2) were randomized to lose a similar weight with an IER (N = 18) or a CER (N = 17) diet over a 12 week period. Macronutrient composition and overall energy restriction (33% reduction) were similar between groups. Body weight/composition, RMR, fasting...

A study on basic theory for CDCC method for three-body model of deuteron scattering

International Nuclear Information System (INIS)

Kawai, Mitsuji

1988-01-01

Recent studies have revealed that the CDCC method is valid for treating the decomposition process involved in deuteron scattering on the basis of a three-body model. However, theoretical support has not been developed for this method. The present study is aimed at determining whether a solution by the CDCC method can be obtained 'correctly' from a 'realistic' model Hamiltonian for deuteron scattering. Some researchers have recently pointed out that there are some problems with the conventional CDCC calculation procedure in view of the general scattering theory. These problems are associated with asymptotic froms of the wave functions, convergence of calculations, and boundary conditions. Considerations show that the problem with asymptotic forms of the wave function is not a fatal defect, though some compromise is necessary. The problem with the convergence of calculations is not very serious either. Discussions are made of the handling of boundary conditions. Thus, the present study indicates that the CDCC method can be applied satisfactorily to actual deuteron scattering, and that the model wave function for the CDCC method is consistent with the model Hamiltonian. (Nogami, K.)

Few-body problem in terms of correlated Gaussians

Science.gov (United States)

Silvestre-Brac, Bernard; Mathieu, Vincent

2007-10-01

In their textbook, Suzuki and Varga [Stochastic Variational Approach to Quantum-Mechanical Few-Body Problems (Springer, Berlin, 1998)] present the stochastic variational method with the correlated Gaussian basis in a very exhaustive way. However, the Fourier transform of these functions and their application to the management of a relativistic kinetic energy operator are missing and cannot be found in the literature. In this paper we present these interesting formulas. We also give a derivation for formulations concerning central potentials.

Low-Thrust Orbital Transfers in the Two-Body Problem

Directory of Open Access Journals (Sweden)

A. A. Sukhanov

2012-01-01

Full Text Available Low-thrust transfers between given orbits within the two-body problem are considered; the thrust is assumed power limited. A simple method for obtaining the transfer trajectories based on the linearization of the motion near reference orbits is suggested. Required calculation accuracy can be reached by means of use of a proper number of the reference orbits. The method may be used in the case of a large number of the orbits around the attracting center; no averaging is necessary in this case. The suggested method also is applicable to the cases of partly given final orbit and if there are constraints on the thrust direction. The method gives an optimal solution to the linearized problem which is not optimal for the original nonlinear problem; the difference between the optimal solutions to the original and linearized problems is estimated using a numerical example. Also examples illustrating the method capacities are given.

Using an isomorphic problem pair to learn introductory physics: Transferring from a two-step problem to a three-step problem

Directory of Open Access Journals (Sweden)

Shih-Yin Lin

2013-10-01

Full Text Available In this study, we examine introductory physics students’ ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. 382 students from a calculus-based and an algebra-based introductory physics course were administered a quiz in the recitation in which they had to learn from a solved problem provided and take advantage of what they learned from it to solve another isomorphic problem (which we call the quiz problem. The solved problem provided has two subproblems while the quiz problem has three subproblems, which is known from previous research to be challenging for introductory students. In addition to the solved problem, students also received extra scaffolding supports that were intended to help them discern and exploit the underlying similarities of the isomorphic solved and quiz problems. The data analysis suggests that students had great difficulty in transferring what they learned from a two-step problem to a three-step problem. Although most students were able to learn from the solved problem to some extent with the scaffolding provided and invoke the relevant principles in the quiz problem, they were not necessarily able to apply the principles correctly. We also conducted think-aloud interviews with six introductory students in order to understand in depth the difficulties they had and explore strategies to provide better scaffolding. The interviews suggest that students often superficially mapped the principles employed in the solved problem to the quiz problem without necessarily understanding the governing conditions underlying each principle and examining the applicability of the principle in the new situation in an in-depth manner. Findings suggest that more scaffolding is needed to help students in transferring from a two-step problem to a three-step problem and applying the physics principles appropriately. We outline a few

Using an isomorphic problem pair to learn introductory physics: Transferring from a two-step problem to a three-step problem

Science.gov (United States)

Lin, Shih-Yin; Singh, Chandralekha

2013-12-01

In this study, we examine introductory physics students’ ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. 382 students from a calculus-based and an algebra-based introductory physics course were administered a quiz in the recitation in which they had to learn from a solved problem provided and take advantage of what they learned from it to solve another isomorphic problem (which we call the quiz problem). The solved problem provided has two subproblems while the quiz problem has three subproblems, which is known from previous research to be challenging for introductory students. In addition to the solved problem, students also received extra scaffolding supports that were intended to help them discern and exploit the underlying similarities of the isomorphic solved and quiz problems. The data analysis suggests that students had great difficulty in transferring what they learned from a two-step problem to a three-step problem. Although most students were able to learn from the solved problem to some extent with the scaffolding provided and invoke the relevant principles in the quiz problem, they were not necessarily able to apply the principles correctly. We also conducted think-aloud interviews with six introductory students in order to understand in depth the difficulties they had and explore strategies to provide better scaffolding. The interviews suggest that students often superficially mapped the principles employed in the solved problem to the quiz problem without necessarily understanding the governing conditions underlying each principle and examining the applicability of the principle in the new situation in an in-depth manner. Findings suggest that more scaffolding is needed to help students in transferring from a two-step problem to a three-step problem and applying the physics principles appropriately. We outline a few possible strategies

Computational Nuclear Quantum Many-Body Problem: The UNEDF Project

OpenAIRE

Bogner, Scott; Bulgac, Aurel; Carlson, Joseph A.; Engel, Jonathan; Fann, George; Furnstahl, Richard J.; Gandolfi, Stefano; Hagen, Gaute; Horoi, Mihai; Johnson, Calvin W.; Kortelainen, Markus; Lusk, Ewing; Maris, Pieter; Nam, Hai Ah; Navratil, Petr

2013-01-01

The UNEDF project was a large-scale collaborative effort that applied high-performance computing to the nuclear quantum many-body problem. UNEDF demonstrated that close associations among nuclear physicists, mathematicians, and computer scientists can lead to novel physics outcomes built on algorithmic innovations and computational developments. This review showcases a wide range of UNEDF science results to illustrate this interplay.

TOPICAL PROBLEMS OF PROVIDING LAWFULNESS IN PRELIMINARY INVESTIGATION BODIES

Directory of Open Access Journals (Sweden)

Elnara Islamova

2015-09-01

Full Text Available This article examines current problems of reviewing crime reports of private prosecution by the preliminary investigation bodies, and the role of the prosecutor in providing lawfulness in this process. Issues are formulated to be clarified by the prosecutor in exercising supervision over the enforcement of the law in the receipt, registration and reviewing of the crime reports of private prosecution.

Changes in Body Mass Index and Stoma Related Problems in the Elderly

Science.gov (United States)

Skeps, Raymond; McMullen, Carmit K.; Wendel, Christopher S.; Bulkley, Joanna; Grant, Marcia; Mohler, Jane; Hornbrook, Mark C.; Krouse, Robert S.; Herrinton, Lisa J.

2012-01-01

Objectives Weight gain can cause retraction of an intestinal stoma, possibly resulting in difficulty with wafer and pouch fit, daily care challenges, and discomfort. This cross-sectional study examined the association between body mass index (BMI) and ostomy-related problems among long-term (>5 years post-diagnosis) colorectal cancer (CRC) survivors. Materials and Methods CRC survivors from three Kaiser Permanente Regions completed a mailed survey. The response rate for those with an ostomy was 53% (283/529). Questions included stoma-related problems and time to conduct daily ostomy care. Poisson regression evaluated associations between report of problems and change in BMI. Our analysis sample included 235 survivors. Results Sample was 76% ≥65 years of age. Since their surgeries, BMI remained stable in 44% (ST), decreased in 20% (DE), and increased in 35% (IN) of survivors. Compared to ST, male IN (RR 2.15 [1.09–4.25]) and female DE (RR 5.06 [1.26–25.0]) were more likely to spend more than 30 minutes per day on stoma care. IN (vs. ST) were more likely to report interference with clothing (RR 1.51 [1.06–2.17]) and other stoma-related problems (RR 2.32 [1.30–4.14]). Survivors who were obese at time of survey were more likely to report interference with clothing (RR 1.88 [1.38–2.56]) and other stoma-related problems (RR 1.68 [1.07–2.65]). Conclusion A change in BMI is associated with ostomy-related problems among long-term CRC survivors. Equipment and care practices may need to be adapted for changes in abdominal shape. Health care providers should caution that a significant increase or decrease in BMI may cause ostomy-related problems. PMID:24071496

Addressing communications between Regulatory Body and TSO: perceptions and problems

International Nuclear Information System (INIS)

Salati de Almeida, I.P.

2007-01-01

The use of TSO assistance by the Regulatory Bodies is a way of facing the complexity of the technology and issues to be dealt with in the licensing and controlling process in the nuclear area. Although both TSO and Regulatory Body are well prepared and adjusted, the nature and environment of TSO work is rather different from the regulators. Some of the TSO members act as a consultant, giving expert advice to the regulators in a specific subject, some are in charge of inspections and audits, others do the job together with the regulators. The way that a TSO member perceives the work to be done, however, often creates different perspectives for questions related to the licensing and controlling process. These perceptions are usually a source of problems between the two partners, regulators and TSO members. In this paper some of this kind of problems are raised and suggestions of how to deal with them are proposed for discussion. (author)

Restricting wolves risks escape

Science.gov (United States)

Mech, L. David; Ballard, Warren; Bangs, Ed; Ream, Bob

2010-01-01

Implementing the proposal set forth by Licht and colleagues (BioScience 60: 147–153) requires restricting wolves to tiny "islands," areas that are magnitudes smaller than the ranges of most wolf populations. Wolves naturally have large ranges; restricting their spatial needs increases the risk of wolves escaping, exacerbating public relations and political and legal problems.

Assessment of mechanical and three-body abrasive wear peculiarity ...

Indian Academy of Sciences (India)

directional fabric reinforcement offers a unique solution for ... showed good performance to the three-body abrasive wear. .... plied by the Pioneer Chemical Company, Delhi, India. ..... Theoretical and measured densities of composites, along.

Three-body decays: structure, decay mechanism and fragment properties

International Nuclear Information System (INIS)

Alvarez-Rodriguez, R.; Jensen, A.S.; Fedorov, D.V.; Fynbo, H.O.U.; Kirsebom, O.S.; Garrido, E.

2009-01-01

We discuss the three-body decay mechanisms of many-body resonances. R-matrix sequential description is compared with full Faddeev computation. The role of the angular momentum and boson symmetries is also studied. As an illustration we show the computed ?-particle energy distribution after the decay of 12 C(1 + ) resonance at 12.7 MeV. This article is based on the presentation by R. Alvarez-Rodriguez at the Fifth Workshop on Critical Stability, Erice, Sicily. (author)

Restrictions and Proportionality

DEFF Research Database (Denmark)

Werlauff, Erik

2009-01-01

The article discusses three central aspects of the freedoms under European Community law, namely 1) the prohibition against restrictions as an important extension of the prohibition against discrimination, 2) a prohibition against exit restrictions which is just as important as the prohibition...... against host country restrictions, but which is often not recognised to the same extent by national law, and 3) the importance of also identifying and recognising an exit restriction, so that it is possible to achieve the required test of appropriateness and proportionality in relation to the rule...

Algebraic diagrammatic construction formalism with three-body interactions

Science.gov (United States)

Raimondi, Francesco; Barbieri, Carlo

2018-05-01

Background: Self-consistent Green's function theory has recently been extended to the basic formalism needed to account for three-body interactions [Carbone, Cipollone, Barbieri, Rios, and Polls, Phys. Rev. C 88, 054326 (2013), 10.1103/PhysRevC.88.054326]. The contribution of three-nucleon forces has so far been included in ab initio calculations on nuclear matter and finite nuclei only as averaged two-nucleon forces. Purpose: We derive the working equations for all possible two- and three-nucleon terms that enter the expansion of the self-energy up to the third order, thus including the interaction-irreducible (i.e., not averaged) diagrams with three-nucleon forces that have been previously neglected. Methods: We employ the algebraic diagrammatic construction up to the third order as an organization scheme for generating a nonperturbative self-energy, in which ring (particle-hole) and ladder (particle-particle) diagrams are resummed to all orders. Results: We derive expressions of the static and dynamic self-energy up to the third order, by taking into account the set of diagrams required when either the skeleton or nonskeleton expansions of the single-particle propagator are assumed. A hierarchy of importance among different diagrams is revealed, and a particular emphasis is given to a third-order diagram [see Fig. 2(c)] that is expected to play a significant role among those featuring an interaction-irreducible three-nucleon force. Conclusion: A consistent formalism to resum at infinite order correlations induced by three-nucleon forces in the self-consistent Green's function theory is now available and ready to be implemented in the many-body solvers.

Can alginate-based preloads increase weight loss beyond calorie restriction? A pilot study in obese individuals.

Science.gov (United States)

Georg Jensen, M; Kristensen, M; Astrup, A

2011-12-01

This randomized, controlled, 2-week intervention study in 24 obese subjects tested the effect on body weight loss and gastrointestinal tolerance of consuming low viscous alginate fibre-based preloads of 3% concentration (500 ml volume) three times a day as an adjuvant to a calorie-restricted diet. The pilot study showed that intake of the alginate preloads was moderately acceptable to the majority of subjects but did not produce additional body weight loss beyond calorie restriction (-1.42 ± 0.38 kg) (n=12) compared to control group (-1.56 ± 0.21 kg) (n=8). These results do not support that alginate supplementation enhance the weight loss effects of a hypo-caloric diet, but a sufficiently powered long-term study is needed to explore whether alginate could be an aid for improving weight loss during caloric-restriction. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of feed restriction and feeding plans on performance, slaughter traits and body composition of growing rabbits

Directory of Open Access Journals (Sweden)

Marco Birolo

2017-06-01

Full Text Available Two feeding systems (L, ad libitum vs. R, feed restriction were combined with 3 feeding plans (MM, MH, HH to evaluate the effects on performance, slaughter results, body composition and nitrogen balance of 300 commercial crossbred rabbits kept individually from weaning to slaughter (34-70 d of age. The R rabbits were fed from 80% (first days on trial to 100% (end of 3rd wk of ad libitum intake, whereafter R rabbits had free access to feed. The 3 feeding plans were: MM plan, M diet with moderate digestible energy (DE content, 10.6 MJ/kg, throughout the trial; HH plan, H diet with high DE content, 11.1 MJ/kg, throughout the trial; MH plan, M diet for the first 3 wk and H diet for the last 2 wk. Feed restriction did not affect nutrient digestibility, growth rate on the whole trial and slaughter results, but improved feed conversion (2.96 vs. 2.89 in L and R rabbits, respectively; P<0.01 and reduced N excretion (2.16 vs. 2.07 g excreted N/d, in L and R rabbits; P<0.05. At the end of the first period (55 d, R rabbits showed lower empty body protein, lipid, and gross energy gains than L rabbits, but differences disappeared within the end of the trial. The HH plan improved feed conversion (2.97 vs. 2.89 for MM vs. HH; P<0.05, but increased excreted N (2.03 vs. 2.17 g/d; P<0.001 in comparison with the MM plan due to the higher digestible protein/DE ratio of H diet, whereas the MH plan showed intermediate results. In conclusion, a moderate feed restriction during post weaning improved feed conversion and reduced N excretion without negative effects on growth or slaughter results. Moreover, N excretion was confirmed to depend largely on dietary nitrogen content.

Weight and Body Composition Changes during the First Three Years of College

Directory of Open Access Journals (Sweden)

Sareen S. Gropper

2012-01-01

Full Text Available Differences in weight, body mass index (BMI, percent and absolute body fat, fat-free mass, and waist circumference were investigated in a group of males and females during the first three years (from 2007 to 2010 of college. Significant three-year gains were observed for weight 2.1±4.7 kg, BMI 0.7±1.6 kg/m2, percent body fat 2.7±3.3%, and fat mass 2.3±3.5 kg. A significant loss of fat-free mass, −0.5 kg, was observed among females. Absolute gains in weight, BMI, and percent and absolute body fat were highest during the freshman year, followed by the junior year, and lowest during the sophomore year. Among the 70% of students gaining weight over the three years, weight gain averaged 4.3 kg. The numbers of females with over 30% body fat doubled, and the number of males with over 20% body fat increased fivefold. Initially 15% of students were classified as obese/overweight and 79% normal weight; by the end of the junior year, 24% were obese/overweight and 70% were normal weight. Efforts on college campuses to promote healthy lifestyles among its student population are needed throughout the college years.

Three-body interactions in sociophysics and their role in coalition forming

Science.gov (United States)

Naumis, Gerardo G.; Samaniego-Steta, F.; del Castillo-Mussot, M.; Vázquez, G. J.

2007-06-01

An study of the effects of three-body interactions in the process of coalition formation is presented. In particular, we modify a spin glass model of bimodal propensities and also a Potts model in order to include a particular three-body Hamiltonian that reproduces the main features of the required interactions. The model can be used to study conflicts, political struggles, political parties, social networks, wars and organizational structures. As an application, we analyze a simplified model of the Iraq war.

Parallel Implementation of Numerical Solution of Few-Body Problem Using Feynman's Continual Integrals

Science.gov (United States)

Naumenko, Mikhail; Samarin, Viacheslav

2018-02-01

Modern parallel computing algorithm has been applied to the solution of the few-body problem. The approach is based on Feynman's continual integrals method implemented in C++ programming language using NVIDIA CUDA technology. A wide range of 3-body and 4-body bound systems has been considered including nuclei described as consisting of protons and neutrons (e.g., 3,4He) and nuclei described as consisting of clusters and nucleons (e.g., 6He). The correctness of the results was checked by the comparison with the exactly solvable 4-body oscillatory system and experimental data.

Effect of three-body forces on the phase behavior of charged colloids

International Nuclear Information System (INIS)

Wu, J. Z.; Bratko, D.; Blanch, H. W.; Prausnitz, J. M.

2000-01-01

Statistical-thermodynamic theory for predicting the phase behavior of a colloidal solution requires the pair interaction potential between colloidal particles in solution. In practice, it is necessary to assume pairwise additivity for the potential of mean force between colloidal particles, but little is known concerning the validity of this assumption. This paper concerns interaction between small charged colloids, such as surfactant micelles or globular proteins, in electrolyte solutions and the multibody effect on phase behavior. Monte Carlo simulations for isolated colloidal triplets in equilateral configurations show that, while the three-body force is repulsive when the three particles are near contact, it becomes short-ranged attractive at further separations, contrary to a previous study where the triplet force is attractive at all separations. The three-body force arises mainly from hard-sphere collisions between colloids and small ions; it is most significant in solutions of monovalent salt at low concentration where charged colloids experience strong electrostatic interactions. To illustrate the effect of three-body forces on the phase behavior of charged colloids, we calculated the densities of coexisting phases using van der Waals-type theories for colloidal solutions and for crystals. For the conditions investigated in this work, even though the magnitude of the three-body force may be as large as 10% of the total force at small separations, three-body forces do not have a major effect on the densities of binary coexisting phases. However, coexisting densities calculated using Derjaguin-Landau-Verwey-Overbeek theory are much different from those calculated using our simulated potential of mean force. (c) 2000 American Institute of Physics

Critical temperature of liquid-gas phase transition for hot nuclear matter and three-body force effect

International Nuclear Information System (INIS)

Zuo Wei; Lu Guangcheng; Li Zenghua; Luo Peiyan; Chinese Academy of Sciences, Beijing

2005-01-01

The finite temperature Brueckner-Hartree-Fock (FTBHF) approach is extended by introducing a microscopic three-body force. Within the extended approach, the three-body force effects on the equation of state of hot nuclear matter and its temperature dependence have been investigated. The critical properties of the liquid-gas phase transition of hot nuclear matter have been calculated. It is shown that the three-body force provides a repulsive contribution to the equation of state of hot nuclear matter. The repulsive effect of the three-body force becomes more pronounced as the density and temperature increase and consequently inclusion of the three-body force contribution in the calculation reduces the predicted critical temperature from about 16 MeV to about 13 MeV. By separating the contribution originated from the 2σ-exchange process coupled to the virtual excitation of a nucleon-antinucleon pair from the full three-body force, the connection between the three-body force effect and the relativistic correction from the Dirac-Brueckner-Hartree-Fock has been explored. It turns out that the contribution of the 2σ-N(N-bar) part is more repulsive than that of the full three-body force and the calculated critical temperature is about 11 MeV if only the 2σ-N(N-bar) component of the three-body force is included which is lower than the value obtained in the case of including the full three-body force and is close to the value predicted by the Dirac-Brueckner-Hartree-Fock (DBHF) approach. Our result provides a reasonable explanation for the discrepancy between the values of critical temperature predicted from the FTBHF approach including the three-body force and the DBHF approach. (authors)

Three Body Decays of D0 and DS Mesons

International Nuclear Information System (INIS)

Palano, Antimo

2001-01-01

New generation experiments are providing large data sets for charm physics with statistics which supersede most previous measurements. The Dalitz plot analyses of 3-body charm decays have been performed in the past but these new large and clean samples will allow high precision measurements that were never before possible. The Dalitz plot analysis of three-body decays is a relatively new technique in development for charm physics studies. This method of analysis is the most complete way of analyzing the data since it allows measurement of both decay amplitudes and phases. The final state is the result of the interference of all intermediate states. The significant results provided by these studies are: (1) Accurate measurements of branching fractions; (2) A study of Final State Interactions; (3) A study of CP violation in rates and decay amplitudes; and (4) New input to several old unsolved problems in light meson spectroscopy, in particular to the scalar mesons puzzle. Factorization models assume the weak decay amplitudes to be real. The fact that the observed amplitudes have a relative complex phase is a consequence of final state interaction. CP violation is expected to be small in charm decays (∼ 10 -3 ) [1]. Two amplitudes with different phases are needed: Ae iδA + Be iδB . In singly Cabibbo-suppressed decays penguin terms may provide a weak phase, while Final State Interactions provide a strong phase shift. Under CP the weak phases change sign but the strong ones do not. Any difference between D and (bar D) in the Dalitz plot would be evidence for CP violation. Throughout this paper charge conjugate modes, where not explicit, are implied

(Weakly) three-dimensional caseology

International Nuclear Information System (INIS)

Pomraning, G.C.

1996-01-01

The singular eigenfunction technique of Case for solving one-dimensional planar symmetry linear transport problems is extended to a restricted class of three-dimensional problems. This class involves planar geometry, but with forcing terms (either boundary conditions or internal sources) which are weakly dependent upon the transverse spatial variables. Our analysis involves a singular perturbation about the classic planar analysis, and leads to the usual Case discrete and continuum modes, but modulated by weakly dependent three-dimensional spatial functions. These functions satisfy parabolic differential equations, with a different diffusion coefficient for each mode. Representative one-speed time-independent transport problems are solved in terms of these generalised Case eigenfunctions. Our treatment is very heuristic, but may provide an impetus for more rigorous analysis. (author)

Three-nucleon problem with phase equivalent potentials

International Nuclear Information System (INIS)

Pushkash, O.M.; Shapoval, D.V.; Simenog, I.V.

1991-01-01

The effect of the t-matrix off-shell variations with nonlocal phase equivalent N-N potentials on the three-nucleon parameters is studied. The variations, which lower or increase the tritium binding energy, are revealed. We show that under certain conditions, the three-nucleon low-energy observables are almost insensitive to the high energy behaviour of the negative parts of the scattering phase shifts. The inverse problem method is applied to reconstruct simple S-wave potentials which to provide a unified description of the two-nucleon and low-energy three-nucleon data. 22 refs.; 6 figs. (author)

Effects of three-body interactions in the parametric and modulational instabilities of Bose–Einstein condensates

International Nuclear Information System (INIS)

Wamba, Etienne; Mohamadou, Alidou; Ekogo, Thierry B.; Atangana, Jacque; Kofane, Timoleon C.

2011-01-01

The parametric modulational instability for a discrete nonlinear Schrödinger equation with a cubic–quintic nonlinearity is analyzed. This model describes the dynamics of BECs, with both two- and three-body interatomic interactions trapped in an optical lattice. We identify and discuss the salient features of the three-body interaction in the parametric modulational instability. It is shown that the three-body interaction term can both, shift as well as narrow the window of parametric instability, and also change the behavior of a modulationally stable and parametrically unstable BEC with attractive two-body interaction. We explore this instability through the multiple-scale analysis and identify it numerically. The effect of the three body losses have also been investigated. -- Highlights: ► The parametric MI for the 1D GPE with a cubic–quintic nonlinearity is analyzed. ► The two- and three-body recombination and time-dependent scattering length is considered. ► We generate bright matter waves soliton through MI.

Energy budget, behavior and leptin in striped hamsters subjected to food restriction and refeeding.

Directory of Open Access Journals (Sweden)

Zhi-Jun Zhao

Full Text Available Food restriction induces a loss of body mass that is often followed by rapid regaining of the lost weight when the restriction ends, consequently increasing a risk of development of obesity. To determine the physiological and behavioral mechanisms underlining the regaining, striped hamsters were restricted to 85% of initial food intake for 4 weeks and refed ad libitum for another 4 weeks. Changes in body mass, energy budget, activity, body composition and serum leptin level were measured. Body mass, body fat mass and serum leptin level significantly decreased in food-restricted hamsters, and increased when the restriction ended, showing a short "compensatory growth" rather than over-weight or obesity compared with ad libitum controls. During restriction, the time spent on activity increased significantly, which was opposite to the changes in serum leptin level. Food intake increased shortly during refeeding, which perhaps contributed to the rapid regaining of body mass. No correlation was observed between serum leptin and energy intake, while negative correlations were found in hamsters that were refed for 7 and 28 days. Exogenous leptin significantly decreased the time spent on activity during food restriction and attenuated the increase in food intake during refeeding. This suggests that low leptin in restricted animals may function as a starvation signal to induce an increase in activity behavior, and high leptin likely serves as a satiety signal to prevent activity during refeeding. Leptin may play a crucial role in controlling food intake when the restriction ends, and consequently preventing overweight.

11Li-12C scattering as a four-body problem

International Nuclear Information System (INIS)

Formanek, J.; Lombard, R.J.

1995-01-01

11 Li- 12 C scattering is described as a four-body problem. The succession of approximations required to obtain the simplified approach of Yabana et al(1992) is examined in detail. We found that whereas their simple model is roughly acceptable for total cross sections (with discrepancies of the order of a few per cent), it has dramatic effects on the differential cross section. Beyond the very forward angles, the problem has to be treated in its full complexity; the various possible intermediate approximations generate differential cross sections which deviate noticeably from the correct calculation. (author)

Three-body Supersymmetric Top Decays

CERN Document Server

Belyaev, A; Lola, S; Belyaev, Alexander; Ellis, John; Lola, Smaragda

2000-01-01

We discuss three-body supersymmetric top decays, in schemes both with andwithout R-parity conservation, assuming that sfermion masses are larger thanm_t. We find that MSSM top decays into chargino/neutralino pairs have a strongkinematic suppression in the region of the supersymmetric parameter spaceconsistent with the LEP limits, with a decay width =< 10^{-5} GeV. MSSM topdecays into neutralino pairs have less kinematical suppression, but require aflavour-changing vertex, and are likely to have a smaller rate. On the otherhand, R-violating decays to single charginos, neutralinos and conventionalfermions can be larger for values of the R-violating couplings still permittedby other upper limits. The cascade decays of the charginos and neutralinos maylead to spectacular signals with explicit lepton-number violation, such aslike-sign lepton events.

The self-consistent field model for Fermi systems with account of three-body interactions

Directory of Open Access Journals (Sweden)

Yu.M. Poluektov

2015-12-01

Full Text Available On the basis of a microscopic model of self-consistent field, the thermodynamics of the many-particle Fermi system at finite temperatures with account of three-body interactions is built and the quasiparticle equations of motion are obtained. It is shown that the delta-like three-body interaction gives no contribution into the self-consistent field, and the description of three-body forces requires their nonlocality to be taken into account. The spatially uniform system is considered in detail, and on the basis of the developed microscopic approach general formulas are derived for the fermion's effective mass and the system's equation of state with account of contribution from three-body forces. The effective mass and pressure are numerically calculated for the potential of "semi-transparent sphere" type at zero temperature. Expansions of the effective mass and pressure in powers of density are obtained. It is shown that, with account of only pair forces, the interaction of repulsive character reduces the quasiparticle effective mass relative to the mass of a free particle, and the attractive interaction raises the effective mass. The question of thermodynamic stability of the Fermi system is considered and the three-body repulsive interaction is shown to extend the region of stability of the system with the interparticle pair attraction. The quasiparticle energy spectrum is calculated with account of three-body forces.

Exercise coupled with dietary restriction reduces oxidative stress in male adolescents with obesity.

Science.gov (United States)

Li, Chunyan; Feng, Feihu; Xiong, Xiaoling; Li, Rui; Chen, Ning

2017-04-01

The increased oxidative stress is usually observed in obese population, but the control of body weight by calorie restriction and/or exercise training can ameliorate oxidative stress. In order to evaluate oxidative stress in response to exercise and dietary restriction in obese adolescents, a total of 20 obese volunteers were enrolled in a 4-week intervention program including exercise training and dietary restriction. Body compositions and blood samples were analysed before and after 4-week intervention, and biomarkers associated with oxidative stress were examined. After 4-week exercise training coupled with dietary restriction, physical composition parameters including body mass, body mass index (BMI), lean body mass, body fat mass and fat mass ratio had obvious reduction by 12.43%, 13.51%, 5.83%, 25.05% and 14.52%, respectively. In addition, the activities of antioxidant enzymes, such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) revealed a remarkable enhancement. On the other hand, protein carbonyls (PC) exhibited an obvious reduction. Moreover, total thiols and nitrites with respect to baseline revealed a reducing trend although no significant difference was observed. Therefore, the 4-week exercise intervention coupled with dietary restriction is benefit for the loss of body weight and the mitigation of oxidative stress in obese population so that it can be a recommendable intervention prescription for the loss of body weight.

Effects of the Eccentricity of a Perturbing Third Body on the Orbital Correction Maneuvers of a Spacecraft

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R. C. Domingos

2014-01-01

Full Text Available The fuel consumption required by the orbital maneuvers when correcting perturbations on the orbit of a spacecraft due to a perturbing body was estimated. The main goals are the measurement of the influence of the eccentricity of the perturbing body on the fuel consumption required by the station keeping maneuvers and the validation of the averaged methods when applied to the problem of predicting orbital maneuvers. To study the evolution of the orbits, the restricted elliptic three-body problem and the single- and double-averaged models are used. Maneuvers are made by using impulsive and low thrust maneuvers. The results indicated that the averaged models are good to make predictions for the orbital maneuvers when the spacecraft is in a high inclined orbit. The eccentricity of the perturbing body plays an important role in increasing the effects of the perturbation and the fuel consumption required for the station keeping maneuvers. It is shown that the use of more frequent maneuvers decreases the annual cost of the station keeping to correct the orbit of a spacecraft. An example of an eccentric planetary system of importance to apply the present study is the dwarf planet Haumea and its moons, one of them in an eccentric orbit.

Evaluation of a Mathematical Model of Rat Body Weight Regulation in Application to Caloric Restriction and Drug Treatment Studies.

Science.gov (United States)

Selimkhanov, Jangir; Thompson, W Clayton; Patterson, Terrell A; Hadcock, John R; Scott, Dennis O; Maurer, Tristan S; Musante, Cynthia J

2016-01-01

The purpose of this work is to develop a mathematical model of energy balance and body weight regulation that can predict species-specific response to common pre-clinical interventions. To this end, we evaluate the ability of a previously published mathematical model of mouse metabolism to describe changes in body weight and body composition in rats in response to two short-term interventions. First, we adapt the model to describe body weight and composition changes in Sprague-Dawley rats by fitting to data previously collected from a 26-day caloric restriction study. The calibrated model is subsequently used to describe changes in rat body weight and composition in a 23-day cannabinoid receptor 1 antagonist (CB1Ra) study. While the model describes body weight data well, it fails to replicate body composition changes with CB1Ra treatment. Evaluation of a key model assumption about deposition of fat and fat-free masses shows a limitation of the model in short-term studies due to the constraint placed on the relative change in body composition components. We demonstrate that the model can be modified to overcome this limitation, and propose additional measurements to further test the proposed model predictions. These findings illustrate how mathematical models can be used to support drug discovery and development by identifying key knowledge gaps and aiding in the design of additional experiments to further our understanding of disease-relevant and species-specific physiology.

Evaluation of a Mathematical Model of Rat Body Weight Regulation in Application to Caloric Restriction and Drug Treatment Studies.

Directory of Open Access Journals (Sweden)

Jangir Selimkhanov

Full Text Available The purpose of this work is to develop a mathematical model of energy balance and body weight regulation that can predict species-specific response to common pre-clinical interventions. To this end, we evaluate the ability of a previously published mathematical model of mouse metabolism to describe changes in body weight and body composition in rats in response to two short-term interventions. First, we adapt the model to describe body weight and composition changes in Sprague-Dawley rats by fitting to data previously collected from a 26-day caloric restriction study. The calibrated model is subsequently used to describe changes in rat body weight and composition in a 23-day cannabinoid receptor 1 antagonist (CB1Ra study. While the model describes body weight data well, it fails to replicate body composition changes with CB1Ra treatment. Evaluation of a key model assumption about deposition of fat and fat-free masses shows a limitation of the model in short-term studies due to the constraint placed on the relative change in body composition components. We demonstrate that the model can be modified to overcome this limitation, and propose additional measurements to further test the proposed model predictions. These findings illustrate how mathematical models can be used to support drug discovery and development by identifying key knowledge gaps and aiding in the design of additional experiments to further our understanding of disease-relevant and species-specific physiology.

Relatively high-protein or 'low-carb' energy-restricted diets for body weight loss and body weight maintenance?

Science.gov (United States)

Soenen, Stijn; Bonomi, Alberto G; Lemmens, Sofie G T; Scholte, Jolande; Thijssen, Myriam A M A; van Berkum, Frank; Westerterp-Plantenga, Margriet S

2012-10-10

'Low-carb' diets have been suggested to be effective in body weight (BW) management. However, these diets are relatively high in protein as well. To unravel whether body-weight loss and weight-maintenance depends on the high-protein or the 'low-carb' component of the diet. Body-weight (BW), fat mass (FM), blood- and urine-parameters of 132 participants (age=50 ± 12 yr; BW=107 ± 20 kg; BMI=37 ± 6 kg/m(2); FM=47.5 ± 11.9 kg) were compared after 3 and 12 months between four energy-restricted diets with 33% of energy requirement for the first 3 months, and 67% for the last 9 months: normal-protein normal-carbohydrate (NPNC), normal-protein low-carbohydrate (NPLC); high-protein normal-carbohydrate (HPNC), high-protein low-carbohydrate (HPLC); 24h N-analyses confirmed daily protein intakes for the normal-protein diets of 0.7 ± 0.1 and for the high-protein diets of 1.1 ± 0.2g/kg BW (pvs. NP (-11.5 ± 4 kg; -9.3 ± 0.7 kg) (pvs. NC (-12.3 ± 3 kg; -10.3 ± 1.1 kg) (ns). Diet × time interaction showed HPLC (-14.7 ± 5 kg; -11.9 ± 1.6 kg) vs. HPNC (-13.8 ± 3 kg; -11.9 ± 1.8 kg) (ns); NPLC (-12.2 ± 4 kg; -10.0 ± 0.8 kg) vs. NPNC (-10.7 ± 4 kg; -8.6 ± 0.7 kg) (ns); HPLC vs. NPLC (pvs. NPNC (pvs. NP (-8.9 ± 3 kg; -7.7 ± 0.6 kg) (pvs. NC (11.1 ± 3 kg; 9.3 ± 0.7 kg) (ns). Diet × time interaction showed HPLC (-11.6 ± 5 kg ; -8.2 ± 0.7 kg) vs. HPNC (-14.1 ± 4 kg; -10.0 ± 0.9 kg) (ns); NPNC (-8.2 ± 3 kg; -6.7 ± 0.6 kg) vs. NPLC (-9.7 ± 3 kg; -8.5 ± 0.7 kg) (ns); HPLC vs. NPLC (pvs. NPNC (pvs. all other diets reduced diastolic blood pressure more. Relationships between changes in BW, FM, FFM or metabolic parameters and energy percentage of fat in the diet were not statistically significant. Metabolic profile and fat-free-mass were improved following weight-loss. Body-weight loss and weight-maintenance depends on the high-protein, but not on the 'low-carb' component of the diet, while it is unrelated to the concomitant fat-content of the diet. Copyright �

Identification of three redundant segments responsible for herpes simplex virus 1 ICP0 to fuse with ND10 nuclear bodies.

Science.gov (United States)

Zheng, Yi; Gu, Haidong

2015-04-01

Infected cell protein 0 (ICP0) of herpes simplex virus 1 (HSV-1) is a key regulator in both lytic and latent infections. In lytic infection, an important early event is the colocalization of ICP0 to nuclear domain 10 (ND10), the discrete nuclear bodies that impose restrictions on viral expression. ICP0 contains an E3 ubiquitin ligase that degrades promyelocytic leukemia protein (PML) and Sp100, two major components of ND10, and disperses ND10 to alleviate repression. We previously reported that the association between ICP0 and ND10 is a dynamic process that includes three steps: adhesion, fusion, and retention. ICP0 residues 245 to 474, defined as ND10 entry signal (ND10-ES), is a region required for the fusion step. Without ND10-ES, ICP0 adheres at the ND10 surface but fails to enter. In the present study, we focus on characterizing ND10-ES. Here we report the following. (i) Fusion of ICP0 with ND10 relies on specific sequences located within ND10-ES. Replacement of ND10-ES by the corresponding region from ORF61 of varicella-zoster virus did not rescue ND10 fusion. (ii) Three tandem ND10 fusion segments (ND10-FS1, ND10-FS2, and ND10-FS3), encompassing 200 amino acids within ND10-ES, redundantly facilitate fusion. Each of the three segments is sufficient to independently drive the fusion process, but none of the segments by themselves are necessary for ND10 fusion. Only when all three segments are deleted is fusion blocked. (iii) The SUMO interaction motif located within ND10-FS2 is not required for ND10 fusion but is required for the complete degradation of PML, suggesting that PML degradation and ND10 fusion are regulated by different molecular mechanisms. ND10 nuclear bodies are part of the cell-intrinsic antiviral defenses that restrict viral gene expression upon virus infection. As a countermeasure, infected cell protein 0 (ICP0) of herpes simplex virus 1 (HSV-1) localizes to ND10s, degrades the ND10 organizer, and disperses ND10 components in order to

Three-body interactions and the Landau levels using Nikiforov

Indian Academy of Sciences (India)

In this article, the eigenvalues for the three-body interactions on the line and the Landau levels in the presence of topological defects have been regenerated by the Nikiforov–Uvarov (NU) method. Two exhaustive lists of such exactly solvable potentials are given.

Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women

Directory of Open Access Journals (Sweden)

Silvestre R

2004-11-01

Full Text Available Abstract Objective To compare the effects of isocaloric, energy-restricted very low-carbohydrate ketogenic (VLCK and low-fat (LF diets on weight loss, body composition, trunk fat mass, and resting energy expenditure (REE in overweight/obese men and women. Design Randomized, balanced, two diet period clinical intervention study. Subjects were prescribed two energy-restricted (-500 kcal/day diets: a VLCK diet with a goal to decrease carbohydrate levels below 10% of energy and induce ketosis and a LF diet with a goal similar to national recommendations (%carbohydrate:fat:protein = ~60:25:15%. Subjects 15 healthy, overweight/obese men (mean ± s.e.m.: age 33.2 ± 2.9 y, body mass 109.1 ± 4.6 kg, body mass index 34.1 ± 1.1 kg/m2 and 13 premenopausal women (age 34.0 ± 2.4 y, body mass 76.3 ± 3.6 kg, body mass index 29.6 ± 1.1 kg/m2. Measurements Weight loss, body composition, trunk fat (by dual-energy X-ray absorptiometry, and resting energy expenditure (REE were determined at baseline and after each diet intervention. Data were analyzed for between group differences considering the first diet phase only and within group differences considering the response to both diets within each person. Results Actual nutrient intakes from food records during the VLCK (%carbohydrate:fat:protein = ~9:63:28% and the LF (~58:22:20% were significantly different. Dietary energy was restricted, but was slightly higher during the VLCK (1855 kcal/day compared to the LF (1562 kcal/day diet for men. Both between and within group comparisons revealed a distinct advantage of a VLCK over a LF diet for weight loss, total fat loss, and trunk fat loss for men (despite significantly greater energy intake. The majority of women also responded more favorably to the VLCK diet, especially in terms of trunk fat loss. The greater reduction in trunk fat was not merely due to the greater total fat loss, because the ratio of trunk fat/total fat was also significantly reduced during

Boundary value problems of finite elasticity local theorems on existence, uniqueness, and analytic dependence on data

CERN Document Server

Valent, Tullio

1988-01-01

In this book I present, in a systematic form, some local theorems on existence, uniqueness, and analytic dependence on the load, which I have recently obtained for some types of boundary value problems of finite elasticity. Actually, these results concern an n-dimensional (n ~ 1) formal generalization of three-dimensional elasticity. Such a generalization, be­ sides being quite spontaneous, allows us to consider a great many inter­ esting mathematical situations, and sometimes allows us to clarify certain aspects of the three-dimensional case. Part of the matter presented is unpublished; other arguments have been only partially published and in lesser generality. Note that I concentrate on simultaneous local existence and uniqueness; thus, I do not deal with the more general theory of exis­ tence. Moreover, I restrict my discussion to compressible elastic bodies and I do not treat unilateral problems. The clever use of the inverse function theorem in finite elasticity made by STOPPELLI [1954, 1957a, 1957b]...

Three-dimensional problems of the hydrodynamic interaction between bodies in a viscous fluid in the vicinity of their contact

Czech Academy of Sciences Publication Activity Database

Petrov, A. G.; Kharlamov, Alexander A.

2013-01-01

Roč. 48, č. 5 (2013), s. 577-587 ISSN 0015-4628 R&D Projects: GA ČR(CZ) GA103/09/2066 Grant - others:Development of the Scientific Potential of the Higher Schoo(RU) 2.1.2/3604; Russian Foundation for Basic Research (RU) 11- 01-005355 Institutional support: RVO:67985874 Keywords : lubrication layer theory * viscous and inviscid fluids * thin layer * vicinity of a contact * three-dimensional problems Subject RIV: BK - Fluid Dynamics Impact factor: 0.320, year: 2013

The Schwinger variational principle in the quantum-mechanical three-body problem

International Nuclear Information System (INIS)

Podkopaev, A.P.; Subarev, A.I.; Wrzecionko, J.

1978-01-01

The Schwinger variational principle (SVP) is applied to problems of atomic (e + H scattering), mesoatomic (p(dμ) scattering) and nuclear (pion-deuteron scattering) physics. The convergence of the Schwinger variational iterative method is investigated. It is shown that in some cases there occurs a pathological convergence. It means that the iterative procedure is convergent, but not to the exact solution. The method of strong coupling of channels is reformulated on the basis of SVP. it permits the summation over all closed channels. The obtained equations are applied to the calculations of the low energy scattering parameters of the following processes: e + H → e + H; πd → πd. The dependence on πN scattering lengths and effective radii is investigated. It is shown that the contribution of closed channels to the π - d scattering length is 30 percent

Unitary four-body model

International Nuclear Information System (INIS)

Fonseca, A.C.; Shanley, P.E.

1976-01-01

A field-theoretic model describing nonrelativistic four-body scattering processes is developed. The model is related to Bronzan's extended Lee model, but the allowed interactions are restricted so that the resulting dynamical equations are as simple as possible, yet still exact. Two elementary particles n and a are introduced with the couplings n + n in equilibrium D and a + a in equilibrium. Three-particle processes are generated by the additional coupling D + a in equilibrium α, leading to the possible three-body reactions D + a → D + a and D + a → n + n + a. The four-body sector then involves the 2 → 2 reactions aα → aα and aα → CD, the 2 → 3 reactions aα → Daa and aα → Cnn, and the 2 → 4 reaction aα → nnaa. Off-shell integral equations are obtained for the 2 → 2 amplitudes, and from these, expressions for the 2 → 3 and 2 → 4 amplitudes are constructed. Possible applications and generalizations of the model are discussed

Global solutions to the electrodynamic two-body problem on a straight line

Science.gov (United States)

Bauer, G.; Deckert, D.-A.; Dürr, D.; Hinrichs, G.

2017-06-01

The classical electrodynamic two-body problem has been a long standing open problem in mathematics. For motion constrained to the straight line, the interaction is similar to that of the two-body problem of classical gravitation. The additional complication is the presence of unbounded state-dependent delays in the Coulomb forces due to the finiteness of the speed of light. This circumstance renders the notion of local solutions meaningless, and therefore, straightforward ODE techniques cannot be applied. Here, we study the time-symmetric case, i.e., the Fokker-Schwarzschild-Tetrode (FST) equations, comprising both advanced and retarded delays. We extend the technique developed in Deckert and Hinrichs (J Differ Equ 260:6900-6929, 2016), where existence of FST solutions was proven on the half line, to ensure global existence—a result that had been obtained by Bauer (Ein Existenzsatz für die Wheeler-Feynman-Elektrodynamik, Herbert Utz Verlag, München, 1997). Due to the novel technique, the presented proof is shorter and more transparent but also relies on the idea to employ asymptotic data to characterize solutions.

Using Three-Body Recombination to Extract Electron Temperatures of Ultracold Plasmas

International Nuclear Information System (INIS)

Fletcher, R. S.; Zhang, X. L.; Rolston, S. L.

2007-01-01

Three-body recombination, an important collisional process in plasmas, increases dramatically at low electron temperatures, with an accepted scaling of T e -9/2 . We measure three-body recombination in an ultracold neutral xenon plasma by detecting recombination-created Rydberg atoms using a microwave-ionization technique. With the accepted theory (expected to be applicable for weakly coupled plasmas) and our measured rates, we extract the plasma temperatures, which are in reasonable agreement with previous measurements early in the plasma lifetime. The resulting electron temperatures indicate that the plasma continues to cool to temperatures below 1 K

Paradeisos: A perfect hashing algorithm for many-body eigenvalue problems

Science.gov (United States)

Jia, C. J.; Wang, Y.; Mendl, C. B.; Moritz, B.; Devereaux, T. P.

2018-03-01

We describe an essentially perfect hashing algorithm for calculating the position of an element in an ordered list, appropriate for the construction and manipulation of many-body Hamiltonian, sparse matrices. Each element of the list corresponds to an integer value whose binary representation reflects the occupation of single-particle basis states for each element in the many-body Hilbert space. The algorithm replaces conventional methods, such as binary search, for locating the elements of the ordered list, eliminating the need to store the integer representation for each element, without increasing the computational complexity. Combined with the "checkerboard" decomposition of the Hamiltonian matrix for distribution over parallel computing environments, this leads to a substantial savings in aggregate memory. While the algorithm can be applied broadly to many-body, correlated problems, we demonstrate its utility in reducing total memory consumption for a series of fermionic single-band Hubbard model calculations on small clusters with progressively larger Hilbert space dimension.

On the inherent self-excited macroscopic randomness of chaotic three-body system

OpenAIRE

Liao, Shijun; Li, Xiaoming

2014-01-01

What is the origin of macroscopic randomness (uncertainty)? This is one of the most fundamental open questions for human being. In this paper, 10000 samples of reliable (convergent), multiple-scale (from 1.0E-60 to 100) numerical simulations of a chaotic three-body system indicate that, without any external disturbance, the microscopic inherent uncertainty (in the level of 1.0E-60) due to physical fluctuation of initial positions of the three-body system enlarges exponentially into macroscopi...

Sources of spurious force oscillations from an immersed boundary method for moving-body problems

Science.gov (United States)

Lee, Jongho; Kim, Jungwoo; Choi, Haecheon; Yang, Kyung-Soo

2011-04-01

When a discrete-forcing immersed boundary method is applied to moving-body problems, it produces spurious force oscillations on a solid body. In the present study, we identify two sources of these force oscillations. One source is from the spatial discontinuity in the pressure across the immersed boundary when a grid point located inside a solid body becomes that of fluid with a body motion. The addition of mass source/sink together with momentum forcing proposed by Kim et al. [J. Kim, D. Kim, H. Choi, An immersed-boundary finite volume method for simulations of flow in complex geometries, Journal of Computational Physics 171 (2001) 132-150] reduces the spurious force oscillations by alleviating this pressure discontinuity. The other source is from the temporal discontinuity in the velocity at the grid points where fluid becomes solid with a body motion. The magnitude of velocity discontinuity decreases with decreasing the grid spacing near the immersed boundary. Four moving-body problems are simulated by varying the grid spacing at a fixed computational time step and at a constant CFL number, respectively. It is found that the spurious force oscillations decrease with decreasing the grid spacing and increasing the computational time step size, but they depend more on the grid spacing than on the computational time step size.

Whole Grain Compared with Refined Wheat Decreases the Percentage of Body Fat Following a 12-Week, Energy-Restricted Dietary Intervention in Postmenopausal Women

DEFF Research Database (Denmark)

Kristensen, Mette; Toubro, Søren; Jensen, Morten Georg

2012-01-01

) with whole-grain wheat (WW) for 12 wk on body weight and composition after a 2-wk run-in period of consumption of RW-containing food intake. In this open-label randomized trial, 79 overweight or obese postmenopausal women were randomized to an energy-restricted diet (deficit of approximately 1250 k...

Quantitative feed restriction of Pekin breeder ducks from 3 weeks of ...

African Journals Online (AJOL)

0,01) lower in body mass than those restricted from 8 weeks of age. The aversion of mass loss during this period could have contributed to the improved performance recorded during the laying period. At 60 weeks of age, the ducks restricted in intake from. 3 weeks were still highly significantly (P ",;;0,01) lighter in body mass ...

Effect of three-body interactions on the zero-temperature equation of state of HCP solid 4He

Science.gov (United States)

Barnes, Ashleigh L.; Hinde, Robert J.

2017-03-01

Previous studies have pointed to the importance of three-body interactions in high density 4He solids. However the computational cost often makes it unfeasible to incorporate these interactions into the simulation of large systems. We report the implementation and evaluation of a computationally efficient perturbative treatment of three-body interactions in hexagonal close packed solid 4He utilizing the recently developed nonadditive three-body potential of Cencek et al. This study represents the first application of the Cencek three-body potential to condensed phase 4He systems. Ground state energies from quantum Monte Carlo simulations, with either fully incorporated or perturbatively treated three-body interactions, are calculated in systems with molar volumes ranging from 21.3 cm3/mol down to 2.5 cm3/mol. These energies are used to derive the zero-temperature equation of state for comparison against existing experimental and theoretical data. The equations of state derived from both perturbative and fully incorporated three-body interactions are found to be in very good agreement with one another, and reproduce the experimental pressure-volume data with significantly better accuracy than is obtained when only two-body interactions are considered. At molar volumes below approximately 4.0 cm3/mol, neither two-body nor three-body equations of state are able to accurately reproduce the experimental pressure-volume data, suggesting that below this molar volume four-body and higher many-body interactions are becoming important.

Three-body cluster state in 11B

International Nuclear Information System (INIS)

Kawabata, T.; Akimune, H.; Fujita, H.; Fujita, Y.; Fujiwara, M.; Hara, K.; Hatanaka, K.; Itoh, M.; Kanada-En'yo, Y.; Kishi, S.; Nakanishi, K.; Sakaguchi, H.; Shimbara, Y.; Tamii, A.; Terashima, S.; Uchida, M.; Wakasa, T.; Yasuda, Y.; Yoshida, H.P.; Yosoi, M.

2007-01-01

The cluster structures of the excited states in 11 B are studied by analyzing the isoscalar monopole and quadrupole strengths in the 11 B(d,d ' ) reaction at E d =200 MeV. The excitation strengths are compared with the predictions by the shell-model and antisymmetrized molecular-dynamics (AMD) calculations. It is found that the large monopole strength for the 3/2 3 - state at E x =8.56 MeV is well described by the AMD calculation and is an evidence for a developed three-body 2α+t cluster structure

Theoretical approaches to many-body perturbation theory and the challenges

International Nuclear Information System (INIS)

Barrett, Bruce R

2005-01-01

A brief review of the history of many-body perturbation theory (MBPT) and its applications in nuclear physics is given. Problems regarding its application to nuclear-structure calculations are discussed and analysed. It is concluded that the usefulness of nuclear MBPT in terms of an expansion in the nuclear reaction matrix G for the calculation of effective interactions in shell-model investigations is severely challenged and restricted by the problems and uncertainties connected with this approach. New methods based on unitary transformation approaches have proven to be more accurate and reliable, particularly for light nuclei

Exact Controllability of a Piezoelectric Body. Theory and Numerical Simulation

International Nuclear Information System (INIS)

Miara, Bernadette; Muench, Arnaud

2009-01-01

We study the exact controllability of a three-dimensional body made of a material whose constitutive law introduces an elasticity-electricity coupling. We show that a coupled elastic-electric control acting on the whole boundary of the body drives the system to rest after time large enough. Two-dimensional numerical experiments suggest that controllability can still be achieved by relaxing this restrictive condition using either both controls on a reduced support or elastic control alone

The human body and weightlessness operational effects, problems and countermeasures

CERN Document Server

Thornton, William

2017-01-01

This book focuses on all of the major problems associated with the absence of body weight in space, by analyzing effects, adaption, and re-adaptation upon returning to Earth, using sound scientific principles embedded in a historical context. Serious problems for space travelers range from Space Motion Sickness (SMS) to recently discovered ocular effects that may permanently impair vision. Fluid loss and shifts, spinal changes, and bone and muscle loss are also all results of weightlessness. Starting with a brief definition and history of weightlessness, the authors then address in detail each problem as well as the countermeasures aimed at alleviating them. In some cases, alternative hypotheses regarding what can and should be attempted are also presented. As plans for long-term missions to the Moon and Mars develop, it will be essential to find countermeasures to weightlessness that are effective for missions that could span years.

Communication Reducing Algorithms for Distributed Hierarchical N-Body Problems with Boundary Distributions

KAUST Repository

AbdulJabbar, Mustafa Abdulmajeed

2017-05-11

Reduction of communication and efficient partitioning are key issues for achieving scalability in hierarchical N-Body algorithms like Fast Multipole Method (FMM). In the present work, we propose three independent strategies to improve partitioning and reduce communication. First, we show that the conventional wisdom of using space-filling curve partitioning may not work well for boundary integral problems, which constitute a significant portion of FMM’s application user base. We propose an alternative method that modifies orthogonal recursive bisection to relieve the cell-partition misalignment that has kept it from scaling previously. Secondly, we optimize the granularity of communication to find the optimal balance between a bulk-synchronous collective communication of the local essential tree and an RDMA per task per cell. Finally, we take the dynamic sparse data exchange proposed by Hoefler et al. [1] and extend it to a hierarchical sparse data exchange, which is demonstrated at scale to be faster than the MPI library’s MPI_Alltoallv that is commonly used.

Green function for three-wave coupling problems

International Nuclear Information System (INIS)

Molevich, N E

2001-01-01

The Green function is found for three-wave coupling problems. The function was used for analysis of parametric amplification in dissipative and active media. It is shown that the parametric increment in active media can become exponential. As an example, the nonstationary stimulated scattering of electromagnetic waves by sound and temperatures waves is considered. (nonlinear optical phenomena)

The three-body problem and the equations of dynamics Poincaré’s foundational work on dynamical systems theory

CERN Document Server

Poincaré, Henri

2017-01-01

Here is an accurate and readable translation of a seminal article by Henri Poincaré that is a classic in the study of dynamical systems popularly called chaos theory. In an effort to understand the stability of orbits in the solar system, Poincaré applied a Hamiltonian formulation to the equations of planetary motion and studied these differential equations in the limited case of three bodies to arrive at properties of the equations’ solutions, such as orbital resonances and horseshoe orbits. Poincaré wrote for professional mathematicians and astronomers interested in celestial mechanics and differential equations. Contemporary historians of math or science and researchers in dynamical systems and planetary motion with an interest in the origin or history of their field will find his work fascinating. .

Graphs and an exactly solvable N-body problem in one dimension

Energy Technology Data Exchange (ETDEWEB)

Barucchi, G [Turin Univ. (Italy). Ist. di Fisica Matematica

1980-08-21

The one-dimensional N-body classical problem with inversely quadratic pair potential is considered. A method of explicit construction, by means of graphs, of the constants of the motion is given. It is then shown how to obtain, by means of a computer, the position variables of the particles as numerical functions of time.

Method for solving the problem of nonlinear heating a cylindrical body with unknown initial temperature

Science.gov (United States)

Yaparova, N.

2017-10-01

We consider the problem of heating a cylindrical body with an internal thermal source when the main characteristics of the material such as specific heat, thermal conductivity and material density depend on the temperature at each point of the body. We can control the surface temperature and the heat flow from the surface inside the cylinder, but it is impossible to measure the temperature on axis and the initial temperature in the entire body. This problem is associated with the temperature measurement challenge and appears in non-destructive testing, in thermal monitoring of heat treatment and technical diagnostics of operating equipment. The mathematical model of heating is represented as nonlinear parabolic PDE with the unknown initial condition. In this problem, both the Dirichlet and Neumann boundary conditions are given and it is required to calculate the temperature values at the internal points of the body. To solve this problem, we propose the numerical method based on using of finite-difference equations and a regularization technique. The computational scheme involves solving the problem at each spatial step. As a result, we obtain the temperature function at each internal point of the cylinder beginning from the surface down to the axis. The application of the regularization technique ensures the stability of the scheme and allows us to significantly simplify the computational procedure. We investigate the stability of the computational scheme and prove the dependence of the stability on the discretization steps and error level of the measurement results. To obtain the experimental temperature error estimates, computational experiments were carried out. The computational results are consistent with the theoretical error estimates and confirm the efficiency and reliability of the proposed computational scheme.

A comparison of low-carbohydrate vs. high-carbohydrate diets: energy restriction, nutrient quality and correlation to body mass index.

Science.gov (United States)

Bowman, Shanthy A; Spence, Joseph T

2002-06-01

To evaluate free-living adults' diets that ranged from very low to high amounts of carbohydrate for their energy content, nutritional quality and correlation to Body Mass Index. Adults ages 19 years and older, who had complete dietary intake data on day-1 of the USDA's 1994 to 1996 Continuing Survey of Food Intakes by Individuals (CSFII 1994-1996), were divided into four groups--very low, low, moderate and high carbohydrate--based on the percent total energy from carbohydrate. Mean energy, nutrient, food intakes and Body Mass Index values were compared among the groups. SUDAAN software package was used for the data analysis and pair-wise mean comparisons (p low-fat foods, grain products and fruits. This group also had the lowest sodium intake. Adults eating a high-carbohydrate diet are more likely to have Body Mass Index values below 25. A study of diets of free-living adults in the U.S. showed that diets high in carbohydrate were both energy restrictive and nutritious and may be adopted for successful weight management.

Parallel Implementation of Numerical Solution of Few-Body Problem Using Feynman’s Continual Integrals

Directory of Open Access Journals (Sweden)

Naumenko Mikhail

2018-01-01

Full Text Available Modern parallel computing algorithm has been applied to the solution of the few-body problem. The approach is based on Feynman’s continual integrals method implemented in C++ programming language using NVIDIA CUDA technology. A wide range of 3-body and 4-body bound systems has been considered including nuclei described as consisting of protons and neutrons (e.g., 3,4He and nuclei described as consisting of clusters and nucleons (e.g., 6He. The correctness of the results was checked by the comparison with the exactly solvable 4-body oscillatory system and experimental data.

The mass-damped Riemann problem and the aerodynamic surface force calculation for an accelerating body

International Nuclear Information System (INIS)

Tan, Zhiqiang; Wilson, D.; Varghese, P.L.

1997-01-01

We consider an extension of the ordinary Riemann problem and present an efficient approximate solution that can be used to improve the calculations of aerodynamic forces on an accelerating body. The method is demonstrated with one-dimensional examples where the Euler equations and the body motion are solved in the non-inertial co-ordinate frame fixed to the accelerating body. 8 refs., 6 figs

Altered gut microbiota in female mice with persistent low body weights following removal of post-weaning chronic dietary restriction.

Science.gov (United States)

Chen, Jun; Toyomasu, Yoshitaka; Hayashi, Yujiro; Linden, David R; Szurszewski, Joseph H; Nelson, Heidi; Farrugia, Gianrico; Kashyap, Purna C; Chia, Nicholas; Ordog, Tamas

2016-10-03

Nutritional interventions often fail to prevent growth failure in childhood and adolescent malnutrition and the mechanisms remain unclear. Recent studies revealed altered microbiota in malnourished children and anorexia nervosa. To facilitate mechanistic studies under physiologically relevant conditions, we established a mouse model of growth failure following chronic dietary restriction and examined microbiota in relation to age, diet, body weight, and anabolic treatment. Four-week-old female BALB/c mice (n = 12/group) were fed ad libitum (AL) or offered limited food to abolish weight gain (LF). A subset of restricted mice was treated with an insulin-like growth factor 1 (IGF1) analog. Food access was restored in a subset of untreated LF (LF-RF) and IGF1-treated LF mice (TLF-RF) on day 97. Gut microbiota were determined on days 69, 96-99 and 120 by next generation sequencing of the V3-5 region of the 16S rRNA gene. Microbiota-host factor associations were analyzed by distance-based PERMANOVA and quantified by the coefficient of determination R 2 for age, diet, and normalized body weight change (Δbwt). Microbial taxa on day 120 were compared following fitting with an overdispersed Poisson regression model. The machine learning algorithm Random Forests was used to predict age based on the microbiota. On day 120, Δbwt in AL, LF, LF-RF, and TLF-RF mice was 52 ± 3, -6 ± 1*, 40 ± 3*, and 46 ± 2 % (*, P < 0.05 versus AL). Age and diet, but not Δbwt, were associated with gut microbiota composition. Age explained a larger proportion of the microbiota variability than diet or Δbwt. Random Forests predicted chronological age based on the microbiota and indicated microbiota immaturity in the LF mice before, but not after, refeeding. However, on day 120, the microbiota community structure of LF-RF mice was significantly different from that of both AL and LF mice. IGF1 mitigated the difference from the AL group. Refed groups had a higher

Semiclassical expansion of quantum characteristics for many-body potential scattering problem

International Nuclear Information System (INIS)

Krivoruchenko, M.I.; Fuchs, C.; Faessler, A.

2007-01-01

In quantum mechanics, systems can be described in phase space in terms of the Wigner function and the star-product operation. Quantum characteristics, which appear in the Heisenberg picture as the Weyl's symbols of operators of canonical coordinates and momenta, can be used to solve the evolution equations for symbols of other operators acting in the Hilbert space. To any fixed order in the Planck's constant, many-body potential scattering problem simplifies to a statistical-mechanical problem of computing an ensemble of quantum characteristics and their derivatives with respect to the initial canonical coordinates and momenta. The reduction to a system of ordinary differential equations pertains rigorously at any fixed order in ℎ. We present semiclassical expansion of quantum characteristics for many-body scattering problem and provide tools for calculation of average values of time-dependent physical observables and cross sections. The method of quantum characteristics admits the consistent incorporation of specific quantum effects, such as non-locality and coherence in propagation of particles, into the semiclassical transport models. We formulate the principle of stationary action for quantum Hamilton's equations and give quantum-mechanical extensions of the Liouville theorem on conservation of the phase-space volume and the Poincare theorem on conservation of 2p-forms. The lowest order quantum corrections to the Kepler periodic orbits are constructed. These corrections show the resonance behavior. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

The electron-atom ionization problem

International Nuclear Information System (INIS)

McCarthy, I.E.

1995-02-01

Methods of calculating electron-atom ionization as a three-body problem with Coulomb boundary conditions are considered. In the absence of a fully-valid computational method for a time-independent experiment the approximation is made that the incident electron experiences a screened potential. Approximations involving a final state that obeys the three-body Coulomb boundary condition are compared with the distorted-wave Born approximation and the convergent close-coupling method. 24 refs., 6 figs

Different levels of food restriction reveal genotype-specific differences in learning a visual discrimination task.

Directory of Open Access Journals (Sweden)

Kalina Makowiecki

Full Text Available In behavioural experiments, motivation to learn can be achieved using food rewards as positive reinforcement in food-restricted animals. Previous studies reduce animal weights to 80-90% of free-feeding body weight as the criterion for food restriction. However, effects of different degrees of food restriction on task performance have not been assessed. We compared learning task performance in mice food-restricted to 80 or 90% body weight (BW. We used adult wildtype (WT; C57Bl/6j and knockout (ephrin-A2⁻/⁻ mice, previously shown to have a reverse learning deficit. Mice were trained in a two-choice visual discrimination task with food reward as positive reinforcement. When mice reached criterion for one visual stimulus (80% correct in three consecutive 10 trial sets they began the reverse learning phase, where the rewarded stimulus was switched to the previously incorrect stimulus. For the initial learning and reverse phase of the task, mice at 90%BW took almost twice as many trials to reach criterion as mice at 80%BW. Furthermore, WT 80 and 90%BW groups significantly differed in percentage correct responses and learning strategy in the reverse learning phase, whereas no differences between weight restriction groups were observed in ephrin-A2⁻/⁻ mice. Most importantly, genotype-specific differences in reverse learning strategy were only detected in the 80%BW groups. Our results indicate that increased food restriction not only results in better performance and a shorter training period, but may also be necessary for revealing behavioural differences between experimental groups. This has important ethical and animal welfare implications when deciding extent of diet restriction in behavioural studies.

Restricting carbohydrates to fight head and neck cancer—is this realistic?

International Nuclear Information System (INIS)

Klement, Rainer J.

2014-01-01

Head and neck cancers (HNCs) are aggressive tumors that typically demonstrate a high glycolytic rate, which results in resistance to cytotoxic therapy and poor prognosis. Due to their location these tumors specifically impair food intake and quality of life, so that prevention of weight loss through nutrition support becomes an important treatment goal. Dietary restriction of carbohydrates (CHOs) and their replacement with fat, mostly in form of a ketogenic diet (KD), have been suggested to accommodate for both the altered tumor cell metabolism and cancer-associated weight loss. In this review, I present three specific rationales for CHO restriction and nutritional ketosis as supportive treatment options for the HNC patient. These are (1) targeting the origin and specific aspects of tumor glycolysis; (2) protecting normal tissue from but sensitizing tumor tissue to radiation- and chemotherapy induced cell kill; (3) supporting body and muscle mass maintenance. While most of these benefits of CHO restriction apply to cancer in general, specific aspects of implementation are discussed in relation to HNC patients. While CHO restriction seems feasible in HNC patients the available evidence indicates that its role may extend beyond fighting malnutrition to fighting HNC itself

A novel dietary restriction method for group-housed rats: weight gain and clinical chemistry characterization.

Science.gov (United States)

Kasanen, I H E; Inhilä, K J; Nevalainen, J I; Väisänen, S B; Mertanen, A M O; Mering, S M; Nevalainen, T O

2009-04-01

Laboratory rodents are usually fed ad libitum. Moderate dietary restriction decreases mortality and morbidity compared with ad libitum feeding. There are, however, problems in achieving dietary restriction. Traditional methods of restricted feeding may interfere with the diurnal rhythms of the animals and are not compatible with group-housing of rodents. We have invented a novel method, the diet board, for restricting the feed intake of laboratory rats. The use of the diet board moderately decreased weight gain of rats when compared with ad libitum-fed animals. The diet board retarded skeletal growth only minimally, whereas major differences were found in body fat depositions. Serum free fatty acid, triglyceride and cholesterol values were lower in diet-restricted rats, while the opposite was true for serum creatine kinase. There were no differences in total protein, albumin or alanine aminotransferase. Moreover, differences in interindividual variances in parameters were not detected between the groups; hence this study could not combine the diet board with reduction potential. The diet board provides mild to moderate dietary restriction for group-housed rats and is unlikely to interfere with the diurnal eating rhythm. The diet board can also be seen as a cage furniture item, dividing the open cage space and increasing the structural complexity of the environment. In conclusion, the diet board appears to possess refinement potential when compared with traditional methods of dietary restriction.

The public whole body counting program following the Three Mile Island accident. Technical report, April-September 1979

International Nuclear Information System (INIS)

Gotchy, R.L.; Bores, R.J.

1980-12-01

In early April, 1979 the U.S. Nuclear Regulatory instituted a program to determine whether any radioactivity released as a result of the March 28, 1979 accident at the Three Mile Island Unit-2 was accumulating in members of the general public living near Unit-2. The program used a device called a whole body counter which has the capability of measuring very small quantities of radioactivity in people. There were 753 men, women and children successfully counted; nine of these people were counted a second time, leading to a total of 762 whole body counts. There was no radioactivity identified in any member of the public which could have originated from the radioactive materials released following the accident. Several people with higher than average levels of naturally occurring radioactivity were identified. The counting systems used are briefly described. Technical problems encountered, results and conclusions are discussed

Virtual states, halos and resonances in three-body atomic and nuclear systems

International Nuclear Information System (INIS)

Frederico, T.; Yamashita, M.T.; Tomio, L.

2009-01-01

By considering nuclear and ultracold trapped atomic systems, we review the trajectory of Efimov excited states in the complex plane by changing the two-body scattering lengths and one three-body scale. This article is based on the presentation by T. Frederico at the Fifth Workshop on Critical Stability, Erice, Sicily. (author)

Resonating-group method for nuclear many-body problems

International Nuclear Information System (INIS)

Tang, Y.C.; LeMere, M.; Thompson, D.R.

1977-01-01

The resonating-group method is a microscopic method which uses fully antisymmetric wave functions, treats correctly the motion of the total center of mass, and takes cluster correlation into consideration. In this review, the formulation of this method is discussed for various nuclear many-body problems, and a complex-generator-coordinate technique which has been employed to evaluate matrix elements required in resonating-group calculations is described. Several illustrative examples of bound-state, scattering, and reaction calculations, which serve to demonstrate the usefulness of this method, are presented. Finally, by utilization of the results of these calculations, the role played by the Pauli principle in nuclear scattering and reaction processes is discussed. 21 figures, 2 tables, 185 references

A Single-Machine Two-Agent Scheduling Problem by a Branch-and-Bound and Three Simulated Annealing Algorithms

Directory of Open Access Journals (Sweden)

Shangchia Liu

2015-01-01

Full Text Available In the field of distributed decision making, different agents share a common processing resource, and each agent wants to minimize a cost function depending on its jobs only. These issues arise in different application contexts, including real-time systems, integrated service networks, industrial districts, and telecommunication systems. Motivated by its importance on practical applications, we consider two-agent scheduling on a single machine where the objective is to minimize the total completion time of the jobs of the first agent with the restriction that an upper bound is allowed the total completion time of the jobs for the second agent. For solving the proposed problem, a branch-and-bound and three simulated annealing algorithms are developed for the optimal solution, respectively. In addition, the extensive computational experiments are also conducted to test the performance of the algorithms.

Stability of orbits around a spinning body in a pseudo-Newtonian Hill problem

International Nuclear Information System (INIS)

Steklain, A.F.; Letelier, P.S.

2009-01-01

A pseudo-Newtonian Hill problem based on a potential proposed by Artemova et al. [I.A. Artemova, G. Bjoernsson, I.D. Novikov, Astrophys. J. 461 (1996) 565] is presented. This potential reproduces some of the general relativistic effects due to the spin angular momentum of the bodies, like the dragging of inertial frames. Poincare maps, Lyapunov exponents and fractal escape techniques are employed to study the stability of bounded and unbounded orbits for different spins of the central body

Restrictions on Software for Personal and Professional Use

CERN Multimedia

2004-01-01

A growing number of computer security incidents detected at CERN are due to additional software installed for personal and professional use. As a consequence, the smooth operation of CERN is put at risk and often many hours are lost solving the problems. To reduce this security risk, installation and/or use of software on CERN's computing and network infrastructure needs to be restricted. Therefore: Do NOT install software for personal use Do NOT install 'free' or other software unless you have the expertise to configure and maintain it securely. Please comply to these rules to keep our computer systems safe. Further explanation of these restrictions is at http://cern.ch/security/software-restrictions Restricted software, known to cause security and/or network problems (e.g. KaZaA and other P2P/Peer-to-Peer file sharing applications, Skype P2P telephony software, ICQ, VNC, ...), is listed at: http://cern.ch/security/software-restrictions/list

A complete basis for a perturbation expansion of the general N-body problem

International Nuclear Information System (INIS)

Laing, W Blake; Kelle, David W; Dunn, Martin; Watson, Deborah K

2009-01-01

We discuss a basis set developed to calculate perturbation coefficients in an expansion of the general N-body problem. This basis has two advantages. First, the basis is complete order-by-order for the perturbation series. Second, the number of independent basis tensors spanning the space for a given order does not scale with N, the number of particles, despite the generality of the problem. At first order, the number of basis tensors is 25 for all N, i.e. the problem scales as N 0 , although one would initially expect an N 6 scaling at first order. The perturbation series is expanded in inverse powers of the spatial dimension. This results in a maximally symmetric configuration at lowest order which has a point group isomorphic with the symmetric group, S N . The resulting perturbation series is order-by-order invariant under the N! operations of the S N point group which is responsible for the slower than exponential growth of the basis. In this paper, we demonstrate the completeness of the basis and perform the first test of this formalism through first order by comparing to an exactly solvable fully interacting problem of N particles with a two-body harmonic interaction potential

Singularities in four-body final-state amplitudes

International Nuclear Information System (INIS)

Adhikari, S.K.

1978-01-01

Like three-body amplitudes, four-body amplitudes have subenergy threshold singularities over and above total-energy singularities. In the four-body problem we encounter a new type of subenergy singularity besides the usual two- and three-body subenergy threshold singularities. This singularity will be referred to as ''independent-pair threshold singularity'' and involves pair-subenergy threshold singularities in each of the two independent pair subenergies in four-body final states. We also study the particularly interesting case of resonant two- and three-body interactions in the four-body isobar model and the rapid (singular) dependence of the isobar amplitudes they generate in the four-body phase space. All these singularities are analyzed in the multiple-scattering formalism and it is shown that they arise from the ''next-to-last'' rescattering and hence may be represented correctly by an approximate amplitude which has that rescattering

Green function of a three-dimensional Wick problem

International Nuclear Information System (INIS)

Matveev, V.A.

1988-01-01

An exact solution of a three-dimensional Coulomb Wick-Cutkovsky problem has been obtained which possesses the hidden 0(4)-symmetry. Here we shell give the derivation of the corresponding Green function and consider its connection with the asymptoric behaviour of the scattering amplitude. 9 refs

Variants of early-onset restrictive eating disturbances in middle childhood.

Science.gov (United States)

Kurz, Susanne; van Dyck, Zoé; Dremmel, Daniela; Munsch, Simone; Hilbert, Anja

2016-01-01

This study sought to determine the factor structure of the newly developed self-report screening questionnaire Eating Disturbances in Youth-Questionnaire (EDY-Q) as well as to report the distribution of variants of early-onset restrictive eating disturbances characteristic of avoidant/restrictive food intake disorder (ARFID) in a middle childhood population sample. Using the EDY-Q, a total of 1,444 children aged 8-13 years were screened in elementary schools in Switzerland via self-report. The factor analysis of the 12 items covering ARFID related symptoms was performed using a principal component analysis (PCA). The PCA showed a four factor solution, with clear allocation to the scales covering three variants of early-onset restrictive eating disturbances and weight problems. Inadequate overall food intake was reported by 19.3% of the children, a limited accepted amount of food by 26.1%, and food avoidance based on a specific underlying fear by 5.0%. The postulated factor structure of the EDY-Q was confirmed, further supporting the existence of distinct variants of early-onset restrictive eating disturbances. Avoidant/restrictive eating behavior seems to be a common experience in middle childhood, but results have to be confirmed using validated interviews. © 2015 Wiley Periodicals, Inc.

Incorporation of threshold phenomena in the three-body Coulomb continuum wavefunctions

International Nuclear Information System (INIS)

Berakdar, J.

1996-01-01

In this work a three-body Coulomb wavefunction for the description of two continuum electrons moving in the field of a nucleus is constructed such that the Wannier threshold law for double escape is reproduced and the asymptotic Coulomb boundary conditions as well as the Kato cusp conditions are satisfied. It is shown that the absolute value of the total cross section, as well as the spin asymmetry, are well described by the present approach. Further, the excess-energy sharing between the two escaping electrons is calculated and analysed in light of the Wannier theory predictions. This is the first time an analytical three-body wavefunction is presented which is asymptotically exact and capable of describing threshold phenomena. 37 refs., 3 figs

Three-month-old human infants use vocal cues of body size.

Science.gov (United States)

Pietraszewski, David; Wertz, Annie E; Bryant, Gregory A; Wynn, Karen

2017-06-14

Differences in vocal fundamental ( F 0 ) and average formant ( F n ) frequencies covary with body size in most terrestrial mammals, such that larger organisms tend to produce lower frequency sounds than smaller organisms, both between species and also across different sex and life-stage morphs within species. Here we examined whether three-month-old human infants are sensitive to the relationship between body size and sound frequencies. Using a violation-of-expectation paradigm, we found that infants looked longer at stimuli inconsistent with the relationship-that is, a smaller organism producing lower frequency sounds, and a larger organism producing higher frequency sounds-than at stimuli that were consistent with it. This effect was stronger for fundamental frequency than it was for average formant frequency. These results suggest that by three months of age, human infants are already sensitive to the biologically relevant covariation between vocalization frequencies and visual cues to body size. This ability may be a consequence of developmental adaptations for building a phenotype capable of identifying and representing an organism's size, sex and life-stage. © 2017 The Author(s).

Effect of calorie restriction on spontaneous physical activity and body mass in mice divergently selected for basal metabolic rate (BMR).

Science.gov (United States)

Brzęk, Paweł; Gębczyński, Andrzej K; Książek, Aneta; Konarzewski, Marek

2016-07-01

Spontaneous physical activity (SPA) represents an important component of daily energy expenditures in animals and humans. Intra-specific variation in SPA may be related to the susceptibility to metabolic disease or obesity. In particular, reduced SPA under conditions of limited food availability may conserve energy and prevent loss of body and fat mass ('thrifty genotype hypothesis'). However, both SPA and its changes during food restriction show wide inter-individual variations. We studied the effect of 30% caloric restriction (CR) on SPA in laboratory mice divergently selected for high (H-BMR) and low (L-BMR) basal metabolic rate. Selection increased SPA in the H-BMR line but did not change it in the L-BMR mice. This effect reflected changes in SPA intensity but not SPA duration. CR increased SPA intensity more strongly in the L-BMR line than in the H-BMR line and significantly modified the temporal variation of SPA. However, the initial between-line differences in SPA were not affected by CR. Loss of body mass during CR did not differ between both lines. Our results show that the H-BMR mice can maintain their genetically determined high SPA under conditions of reduced food intake without sacrificing their body mass. We hypothesize that this pattern may reflect the higher flexibility in the energy budget in the H-BMR line, as we showed previously that mice from this line reduced their BMR during CR. These energy savings may allow for the maintenance of elevated SPA in spite of reduced food intake. We conclude that the effect of CR on SPA is in large part determined by the initial level of BMR, whose variation may account for the lack of universal pattern of behavioural responses to CR. Copyright © 2016 Elsevier Inc. All rights reserved.

Computational nuclear quantum many-body problem: The UNEDF project

Science.gov (United States)

Bogner, S.; Bulgac, A.; Carlson, J.; Engel, J.; Fann, G.; Furnstahl, R. J.; Gandolfi, S.; Hagen, G.; Horoi, M.; Johnson, C.; Kortelainen, M.; Lusk, E.; Maris, P.; Nam, H.; Navratil, P.; Nazarewicz, W.; Ng, E.; Nobre, G. P. A.; Ormand, E.; Papenbrock, T.; Pei, J.; Pieper, S. C.; Quaglioni, S.; Roche, K. J.; Sarich, J.; Schunck, N.; Sosonkina, M.; Terasaki, J.; Thompson, I.; Vary, J. P.; Wild, S. M.

2013-10-01

The UNEDF project was a large-scale collaborative effort that applied high-performance computing to the nuclear quantum many-body problem. The primary focus of the project was on constructing, validating, and applying an optimized nuclear energy density functional, which entailed a wide range of pioneering developments in microscopic nuclear structure and reactions, algorithms, high-performance computing, and uncertainty quantification. UNEDF demonstrated that close associations among nuclear physicists, mathematicians, and computer scientists can lead to novel physics outcomes built on algorithmic innovations and computational developments. This review showcases a wide range of UNEDF science results to illustrate this interplay.

Vehicle Routing with Three-dimensional Container Loading Constraints—Comparison of Nested and Joint Algorithms

Science.gov (United States)

Koloch, Grzegorz; Kaminski, Bogumil

2010-10-01

In the paper we examine a modification of the classical Vehicle Routing Problem (VRP) in which shapes of transported cargo are accounted for. This problem, known as a three-dimensional VRP with loading constraints (3D-VRP), is appropriate when transported commodities are not perfectly divisible, but they have fixed and heterogeneous dimensions. In the paper restrictions on allowable cargo positionings are also considered. These restrictions are derived from business practice and they extended the baseline 3D-VRP formulation as considered by Koloch and Kaminski (2010). In particular, we investigate how additional restrictions influence relative performance of two proposed optimization algorithms: the nested and the joint one. Performance of both methods is compared on artificial problems and on a big-scale real life case study.

Hypothesis Designs for Three-Hypothesis Test Problems

OpenAIRE

Yan Li; Xiaolong Pu

2010-01-01

As a helpful guide for applications, the alternative hypotheses of the three-hypothesis test problems are designed under the required error probabilities and average sample number in this paper. The asymptotic formulas and the proposed numerical quadrature formulas are adopted, respectively, to obtain the hypothesis designs and the corresponding sequential test schemes under the Koopman-Darmois distributions. The example of the normal mean test shows that our methods are qu...

Subdeltoid Bursa Tuberculosis with Rice Body Formation–A Case Report

Directory of Open Access Journals (Sweden)

Santosh L. Munde

2015-01-01

Full Text Available Tuberculous tenosynovitis and bursitis account for approximately 1%. A 56 years old female presented with swelling in left shoulder, gradually increasing in size with slight restriction in movement since last three months. X-ray revealed no abnormality of humerus head. Histopathological examination showed granulomatous tissue with multiple rice bodies. A positive culture of mycobacterium tuberculosis confirmed the diagnosis of tuberculosis. We here report a case of subdeltoid bursitis with rice body formation and without active bone and joint tuberculosis.

Coulomb-Sturmian separable expansion approach: Three-body Faddeev calculations for Coulomb-like interactions

International Nuclear Information System (INIS)

Papp, Z.; Plessas, W.

1996-01-01

We demonstrate the feasibility and efficiency of the Coulomb-Sturmian separable expansion method for generating accurate solutions of the Faddeev equations. Results obtained with this method are reported for several benchmark cases of bosonic and fermionic three-body systems. Correct bound-state results in agreement with the ones established in the literature are achieved for short-range interactions. We outline the formalism for the treatment of three-body Coulomb systems and present a bound-state calculation for a three-boson system interacting via Coulomb plus short-range forces. The corresponding result is in good agreement with the answer from a recent stochastic-variational-method calculation. copyright 1996 The American Physical Society

Effect of three-body transformed Hamiltonian (H3) using full ...

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 90; Issue 3 ... Research Article Volume 90 Issue 3 March 2018 Article ID 36 ... Valence universal multireference coupled cluster (VUMRCC) method via eigenvalue independent partitioning has been applied to estimate the effect of three-body transformed Hamiltonian ...

Intrauterine growth restriction

Directory of Open Access Journals (Sweden)

Bernardita Donoso Bernales

2012-07-01

Full Text Available It is estimated that the true prevalence of intrauterine growth restriction is 3-10% of all pregnancies, making this fetal condition one of the most frequent obstetric problems, together with premature labor and premature rupture of membranes. The article stresses the importance of early diagnosis because of the associated risks.

Dynamics of body protein deposition and changes in body composition after sudden changes in amino acid intake: I. Barrows.

Science.gov (United States)

Martínez-Ramírez, H R; Jeaurond, E A; de Lange, C F M

2008-09-01

A study was conducted to evaluate the extent and dynamics of whole body protein deposition and changes in chemical and physical body composition after a period of AA intake restriction in growing barrows with medium lean tissue growth potentials. Forty Yorkshire barrows (initial BW 14.4 +/- 1.6 kg) were scale-fed at 75% of estimated voluntary daily DE intake up to 35 kg of BW and assigned to 1 of 2 diets: AA adequate (AA+; 20% above requirements; NRC, 1998) and AA deficient (AA-; 40% below requirements; restriction phase). Thereafter (re-alimentation phase), pigs from both dietary AA levels were scale-fed or fed ad libitum diets that were not limiting in AA. Body weight gain and body composition, based on serial slaughter, were monitored during the 34-d re-alimentation phase. During the restriction phase AA intake restriction reduced BW gains (556 vs. 410 g/d; P alimentation phase (P > 0.10). Throughout the re-alimentation phase, there were no interactive effects of time, feeding level, and previous AA intake level on growth performance, body protein, and body lipid content (P > 0.10). During the re-alimentation phase, body protein deposition, derived from the linear regression analysis of body protein content vs. time, was not affected by feeding level and previous AA intake level (P > 0.10; 156 g/d for AA- vs. 157 g/d for AA+). Based on BW and body protein content, it can be concluded that no compensatory body protein deposition occurred in barrows, with medium lean tissue growth potential after AA intake restriction between 15 and 35 kg of BW. It is suggested that the upper limit to body protein deposition was the main factor that limited the extent of compensatory body protein deposition in this population of pigs. The concept of an upper limit to body protein deposition may be used to explain why compensatory growth is observed in some studies and not in others.

Estimation of genetic parameters for body weights of Kurdish sheep ...

African Journals Online (AJOL)

Genetic parameters and (co)variance components were estimated by restricted maximum likelihood (REML) procedure, using animal models of kind 1, 2, 3, 4, 5 and 6, for body weight in birth, three, six, nine and 12 months of age in a Kurdish sheep flock. Direct and maternal breeding values were estimated using the best ...

Dairy Intake Enhances Body Weight and Composition Changes during Energy Restriction in 18–50-Year-Old Adults—A Meta-Analysis of Randomized Controlled Trials

Directory of Open Access Journals (Sweden)

Welma Stonehouse

2016-07-01

Full Text Available Background/Aims: A meta-analysis of randomized controlled trials (RCTs was performed to investigate the effects of dairy food or supplements during energy restriction on body weight and composition in 18–50-year-old. Methods: RCTs ≥ 4 weeks comparing the effect of dairy consumption (whole food or supplements with control diets lower in dairy during energy restriction on body weight, fat and lean mass were identified by searching MEDLINE, EMBASE, Pubmed, Cochrane Central and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP until March 2016. Reports were identified and critically appraised in duplicate. Data were pooled using random-effects meta-analysis. Chi2- and I2-statistics indicated heterogeneity. Dose effect was assessed using meta-regression analysis. GRADE guidelines were used to rate the quality (QR of the evidence considering risk of bias, inconsistency, indirectness, imprecision, publication bias and effect estimates. Results: 27 RCTs were reviewed. Participants consumed between 2 and 4 standard servings/day of dairy food or 20–84 g/day of whey protein compared to low dairy control diets, over a median of 16 weeks. A greater reduction in body weight (−1.16 kg [−1.66, −0.66 kg], p < 0.001, I2 = 11%, QR = high, n = 644 and body fat mass (−1.49 kg [−2.06, −0.92 kg], p < 0.001, I2 = 21%, n = 521, QR = high were found in studies largely including women (90% women. These effects were absent in studies that imposed resistance training (QR = low-moderate. Dairy intake resulted in smaller loss of lean mass (all trials pooled: 0.36 kg [0.01, 0.71 kg], p = 0.04, I2 = 64%, n = 651, QR = moderate. No between study dose-response effects were seen. Conclusions: Increased dairy intake as part of energy restricted diets resulted in greater loss in bodyweight and fat mass while attenuating lean mass loss in 18–50-year-old adults. Further research in males is needed to investigate sex effects.

Investigation of halo structure of He by hyperspherical three-body ...

Indian Academy of Sciences (India)

Abstract. Hyperspherical harmonics expansion method is applied to a three-body model of two neutron halo nuclei. Convergence of the expansion has been ensured. A repulsive part is introduced in the interaction between the core and the extra-core neutron, to simulate Pauli principle. Two neutron separation energy ...

Reply to C. M. Will on the axially symmetric two-body problem in general relativity

International Nuclear Information System (INIS)

Cooperstock, F.I.; Lim, P.H.

1985-01-01

The recent paper by Will (1983) is considered which purports to demonstrate that the gravitational radiation which the authors had computed from their model two-body free-fall system is consistent with the so-called quadrupole formula. It is shown that in fact the system presented by Will is different from the authors and that the illegitimate application of the quadrupole formula to the authors system leads to a smaller flux than that which is correctly deduced using general relativity and a proper consideration of nonlinearities. It is demonstrated that a judicious choice of stress release is propagated through the bodies as a superposition of plane and spherical waves leading to pressure fluctuations to the order in question. This underlines the essential distinction between the authors problem and the Will problem. Various aspects of the problem are also discussed. 25 references

Parallel Simulation of Three-Dimensional Free Surface Fluid Flow Problems

International Nuclear Information System (INIS)

BAER, THOMAS A.; SACKINGER, PHILIP A.; SUBIA, SAMUEL R.

1999-01-01

Simulation of viscous three-dimensional fluid flow typically involves a large number of unknowns. When free surfaces are included, the number of unknowns increases dramatically. Consequently, this class of problem is an obvious application of parallel high performance computing. We describe parallel computation of viscous, incompressible, free surface, Newtonian fluid flow problems that include dynamic contact fines. The Galerkin finite element method was used to discretize the fully-coupled governing conservation equations and a ''pseudo-solid'' mesh mapping approach was used to determine the shape of the free surface. In this approach, the finite element mesh is allowed to deform to satisfy quasi-static solid mechanics equations subject to geometric or kinematic constraints on the boundaries. As a result, nodal displacements must be included in the set of unknowns. Other issues discussed are the proper constraints appearing along the dynamic contact line in three dimensions. Issues affecting efficient parallel simulations include problem decomposition to equally distribute computational work among a SPMD computer and determination of robust, scalable preconditioners for the distributed matrix systems that must be solved. Solution continuation strategies important for serial simulations have an enhanced relevance in a parallel coquting environment due to the difficulty of solving large scale systems. Parallel computations will be demonstrated on an example taken from the coating flow industry: flow in the vicinity of a slot coater edge. This is a three dimensional free surface problem possessing a contact line that advances at the web speed in one region but transitions to static behavior in another region. As such, a significant fraction of the computational time is devoted to processing boundary data. Discussion focuses on parallel speed ups for fixed problem size, a class of problems of immediate practical importance

The inverse problem of brain energetics: ketone bodies as alternative substrates

Energy Technology Data Exchange (ETDEWEB)

Calvetti, D; Occhipinti, R [Case Western Reserve University, Department of Mathematics, 10900 Euclid Avenue, Cleveland, OH 44106 (United States); Somersalo, E [Helsinki University of Technology, Institute of Mathematics, P. O. Box 1100, FIN-02015 HUT (Finland)], E-mail: daniela.calvetti@case.edu, E-mail: rossana.occhipinti@case.edu, E-mail: erkki.somersalo@tkk.fi

2008-07-15

Little is known about brain energy metabolism under ketosis, although there is evidence that ketone bodies have a neuroprotective role in several neurological disorders. We investigate the inverse problem of estimating reaction fluxes and transport rates in the different cellular compartments of the brain, when the data amounts to a few measured arterial venous concentration differences. By using a recently developed methodology to perform Bayesian Flux Balance Analysis and a new five compartment model of the astrocyte-glutamatergic neuron cellular complex, we are able to identify the preferred biochemical pathways during shortage of glucose and in the presence of ketone bodies in the arterial blood. The analysis is performed in a minimally biased way, therefore revealing the potential of this methodology for hypothesis testing.

The inverse problem of brain energetics: ketone bodies as alternative substrates

International Nuclear Information System (INIS)

Calvetti, D; Occhipinti, R; Somersalo, E

2008-01-01

Little is known about brain energy metabolism under ketosis, although there is evidence that ketone bodies have a neuroprotective role in several neurological disorders. We investigate the inverse problem of estimating reaction fluxes and transport rates in the different cellular compartments of the brain, when the data amounts to a few measured arterial venous concentration differences. By using a recently developed methodology to perform Bayesian Flux Balance Analysis and a new five compartment model of the astrocyte-glutamatergic neuron cellular complex, we are able to identify the preferred biochemical pathways during shortage of glucose and in the presence of ketone bodies in the arterial blood. The analysis is performed in a minimally biased way, therefore revealing the potential of this methodology for hypothesis testing

The inverse problem of brain energetics: ketone bodies as alternative substrates

Science.gov (United States)

Calvetti, D.; Occhipinti, R.; Somersalo, E.

2008-07-01

Little is known about brain energy metabolism under ketosis, although there is evidence that ketone bodies have a neuroprotective role in several neurological disorders. We investigate the inverse problem of estimating reaction fluxes and transport rates in the different cellular compartments of the brain, when the data amounts to a few measured arterial venous concentration differences. By using a recently developed methodology to perform Bayesian Flux Balance Analysis and a new five compartment model of the astrocyte-glutamatergic neuron cellular complex, we are able to identify the preferred biochemical pathways during shortage of glucose and in the presence of ketone bodies in the arterial blood. The analysis is performed in a minimally biased way, therefore revealing the potential of this methodology for hypothesis testing.

The effect of flexible body armour on pulmonary function.

Science.gov (United States)

Armstrong, Nicola C; Gay, Louise A

2016-05-01

The additional mass and fit of current military in-service body armour (ISBA) can reduce pulmonary function in a way that is characteristic of a restrictive respiratory impairment. This could ultimately impair exercise capacity and military performance. This study compared pulmonary function (forced vital capacity [FVC] and forced expiratory volume in 1 s [FEV1]) in UK ISBA (15.3 kg) and three flexible body armours (BAs) (FA1: 10 kg; FA2: 7.8 kg; FA3: 10 kg) in eight male soldiers. The design of the ballistic plates differed between the BAs to improve the flexibility. FVC and FEV1 were reduced by 4-6%, without reduction in FEV1/FVC for ISBA, FA2 and FA3, when compared to NoBA (p armour caused a mild restrictive ventilatory impairment. However, the design of the armour can be modified to reduce the degree of this impairment. This may lead to improvements in soldier performance during tasks that require body armour.

Photofragment translational spectroscopy of three body dissociations and free radicals

Energy Technology Data Exchange (ETDEWEB)

North, Simon William [Univ. of California, Berkeley, CA (United States)

1995-04-01

This dissertation describes several three-body dissociations and the photodissociation of methyl radicals studied using photofragment translational spectroscopy. The first chapter provides an introduction to three body dissociation, examines current experimental methodology, and includes a discussion on the treatment of photofragment translational spectroscopy data arising from three-body fragmentation. The ultraviolet photodissociation of azomethane into two methyl radicals and nitrogen is discussed in chapter 2. Chapter 3 describes the photodissociation of acetone at 248 nm and 193 nm. At 248 nm the translational energy release from the initial C-C bond cleavage matches the exit barrier height and a comparison with results at 266 nm suggests that T> is invariant to the available energy. A fraction of the nascent CH₃CO radicals spontaneously dissociate following rotational averaging. The T> for the second C-C bond cleavage also matches the exit barrier height. At 193 nm the experimental data can be successfully fit assuming that the dynamics are analogous to those at 248 nm. A simplified model of energy partitioning which adequately describes the experimental results is discussed. Experiments on acetyl halides provide additional evidence to support the proposed acetone dissociation mechanism. A value of 17.0±1.0 kcal/mole for the barrier height, CH₃CO decomposition has been determined. The photodissociation of methyl radical at 193 nm and 212.8 nm is discussed in the chapter 5. The formation of CH₂(¹A_l) and H (²S) was the only single photon dissociation pathway observed at both wavelengths.

Two- and three-cluster decays of light nuclei within a hyperspherical harmonics approach

Science.gov (United States)

Vasilevsky, V. S.; Lashko, Yu. A.; Filippov, G. F.

2018-06-01

We consider a set of three-cluster systems (4He, 7Li, 7Be, 8Be, 10Be) within a microscopic model which involves hyperspherical harmonics to represent intercluster motion. We selected three-cluster systems which have at least one binary channel. Our aim is to study whether hyperspherical harmonics are able, and under what conditions, to describe two-body channel(s) (nondemocratic motion) or if they are suitable for describing the three-cluster continuum only (democratic motion). It is demonstrated that a rather restricted number of hyperspherical harmonics allows us to describe bound states and scattering states in the two-body continuum for a three-cluster system.

Many-body effects in the mesoscopic x-ray edge problem

International Nuclear Information System (INIS)

Hentschel, Martina; Roeder, Georg; Ullmo, Denis

2007-01-01

Many-body phenomena, a key interest in the investigation of bulk solid state systems, are studied here in the context of the x-ray edge problem for mesoscopic systems. We investigate the many-body effects associated with the sudden perturbation following the x-ray exciton of a core electron into the conduction band. For small systems with dimensions at the nanoscale we find considerable deviations from the well-understood metallic case where Anderson orthogonality catastrophe and the Mahan-Nozieres-DeDominicis response cause characteristic deviations of the photoabsorption cross section from the naive expectation. Whereas the K-edge is typically rounded in metallic systems, we find a slightly peaked K-edge in generic mesoscopic systems with chaotic-coherent electron dynamics. Thus the behavior of the photoabsorption cross section at threshold depends on the system size and is different for the metallic and the mesoscopic case. (author)

Dietary fat and not calcium supplementation or dairy product consumption is associated with changes in anthropometrics during a randomized, placebo-controlled energy-restriction trial

Directory of Open Access Journals (Sweden)

Zemel Michael B

2011-10-01

Full Text Available Abstract Insufficient calcium intake has been proposed to cause unbalanced energy partitioning leading to obesity. However, weight loss interventions including dietary calcium or dairy product consumption have not reported changes in lipid metabolism measured by the plasma lipidome. Methods The objective of this study was to determine the relationships between dairy product or supplemental calcium intake with changes in the plasma lipidome and body composition during energy restriction. A secondary objective of this study was to explore the relationships among calculated macronutrient composition of the energy restricted diet to changes in the plasma lipidome, and body composition during energy restriction. Overweight adults (n = 61 were randomized into one of three intervention groups including a deficit of 500kcal/d: 1 placebo; 2 900 mg/d calcium supplement; and 3 3-4 servings of dairy products/d plus a placebo supplement. Plasma fatty acid methyl esters of cholesterol ester, diacylglycerol, free fatty acids, lysophosphatidylcholine, phosphatidylcholine, phosphatidylethanolamine and triacylglycerol were quantified by capillary gas chromatography. Results After adjustments for energy and protein (g/d intake, there was no significant effect of treatment on changes in weight, waist circumference or body composition. Plasma lipidome did not differ among dietary treatment groups. Stepwise regression identified correlations between reported intake of monounsaturated fat (% of energy and changes in % lean mass (r = -0.44, P P Conclusions Dairy product consumption or calcium supplementation during energy restriction over the course of 12 weeks did not affect plasma lipids. Independent of calcium and dairy product consumption, short-term energy restriction altered body composition. Reported dietary fat composition of energy restricted diets was associated with the degree of change in body composition in these overweight and obese individuals.

Problems occurred in prospecting and mining of a broken thick large uranium ore body and improvement scheme

International Nuclear Information System (INIS)

Hu Longfei; Fang Yang; Wang Yishun; Wang Long

2014-01-01

In prospecting and mining of a broken thick large uranium ore body, uncertain prospecting and shallow-hole shrinkage mining method resulted in large dilution rate and resource waste problems. Aimed at these problems, improvement schemes of enhancing the strength force of 'drilling prospecting instead of pit prospecting' and employing filling method stoping ore body were applied, and improvement result was analyzed. Experience was accumulated and evidence was provided for late prospecting and stoping work. (authors)

Numerical solutions of a three-point boundary value problem with an ...

African Journals Online (AJOL)

Numerical solutions of a three-point boundary value problem with an integral condition for a third-order partial differential equation by using Laplace transform method Solutions numeriques d'un probleme pour une classe d'equations differentielles d'ordr.

Calorie restriction increases muscle mitochondrial biogenesis in healthy humans.

Directory of Open Access Journals (Sweden)

Anthony E Civitarese

2007-03-01

Full Text Available Caloric restriction without malnutrition extends life span in a range of organisms including insects and mammals and lowers free radical production by the mitochondria. However, the mechanism responsible for this adaptation are poorly understood.The current study was undertaken to examine muscle mitochondrial bioenergetics in response to caloric restriction alone or in combination with exercise in 36 young (36.8 +/- 1.0 y, overweight (body mass index, 27.8 +/- 0.7 kg/m(2 individuals randomized into one of three groups for a 6-mo intervention: Control, 100% of energy requirements; CR, 25% caloric restriction; and CREX, caloric restriction with exercise (CREX, 12.5% CR + 12.5% increased energy expenditure (EE. In the controls, 24-h EE was unchanged, but in CR and CREX it was significantly reduced from baseline even after adjustment for the loss of metabolic mass (CR, -135 +/- 42 kcal/d, p = 0.002 and CREX, -117 +/- 52 kcal/d, p = 0.008. Participants in the CR and CREX groups had increased expression of genes encoding proteins involved in mitochondrial function such as PPARGC1A, TFAM, eNOS, SIRT1, and PARL (all, p < 0.05. In parallel, mitochondrial DNA content increased by 35% +/- 5% in the CR group (p = 0.005 and 21% +/- 4% in the CREX group (p < 0.004, with no change in the control group (2% +/- 2%. However, the activity of key mitochondrial enzymes of the TCA (tricarboxylic acid cycle (citrate synthase, beta-oxidation (beta-hydroxyacyl-CoA dehydrogenase, and electron transport chain (cytochrome C oxidase II was unchanged. DNA damage was reduced from baseline in the CR (-0.56 +/- 0.11 arbitrary units, p = 0.003 and CREX (-0.45 +/- 0.12 arbitrary units, p = 0.011, but not in the controls. In primary cultures of human myotubes, a nitric oxide donor (mimicking eNOS signaling induced mitochondrial biogenesis but failed to induce SIRT1 protein expression, suggesting that additional factors may regulate SIRT1 content during CR.The observed increase in

Unitary three-body calculation of nucleon-nucleon scattering

International Nuclear Information System (INIS)

Tanabe, H.; Ohta, K.

1986-07-01

We calculate nucleon-nucleon elastic scattering phase parameters based on a unitary, relativistic, pion-exchange model. The results are highly dependent on the off-shell amplitudes of πN scattering. The isobar-dominated model for the P 33 interaction leads to too small pion production rates owing to its strong suppression of off-shell pions. We propose to expand the idea of the Δ-isobar model in such a manner as to incorporate a background (non-pole) interaction. The two-potential model, which was first applied to the P 11 partial wave by Mizutani and Koltun, is applied also to the P 33 wave. Our phenomenological model for πN interaction in the P 33 partial wave differs from the conventional model only in its off-shell extrapolation, and has two different variants for the πN → Δ vertex. The three-body approach of Kloet and Silbar is extended such that the background interactions can be included straightfowardly. We make detailed comparisons of the new model with the conventional one and find that our model adequately reproduces the 1 D 2 phase parameters as well as those of peripheral partial waves. We also find that the longitudinal total cross section difference Δσ L (pp → NNπ) comes closer to the data compared to Kloet and Silbar. We discuss about the backward pion propagation in the three-body calculation, and the Pauli-principle violating states for the background P 11 interaction. (author)

The quantum N-body problem in the mean-field and semiclassical regime.

Science.gov (United States)

Golse, François

2018-04-28

The present work discusses the mean-field limit for the quantum N -body problem in the semiclassical regime. More precisely, we establish a convergence rate for the mean-field limit which is uniform as the ratio of Planck constant to the action of the typical single particle tends to zero. This convergence rate is formulated in terms of a quantum analogue of the quadratic Monge-Kantorovich or Wasserstein distance. This paper is an account of some recent collaboration with C. Mouhot, T. Paul and M. Pulvirenti.This article is part of the themed issue 'Hilbert's sixth problem'. © 2018 The Author(s).

Proceedings of the meeting on few-body problems in high and medium energy physics

International Nuclear Information System (INIS)

Yukawa, T.

1985-12-01

The study meeting on few-body problems in high and medium energy physics was held from October 3 to 5, 1985, at National Laboratory for High Energy Physics. Two meetings were held already concerning few body physics, but most of the participants were theorists. In this meeting, high priority was put on the attendance of experimental physicists. As a bridge between particle and nuclear physics, the few body physics in an intermediate energy region has become important recently. The topics in this meeting were meson spectroscopy, baryonium, kaon physics, muonic fusion, dibaryon, φNN system, quarks and skyrmions, NN correlation, and symmetry test in few-body system. The gists of the papers presented are collected in this book. (Kako, I.)

Algebraic internal wave solitons and the integrable Calogero--Moser--Sutherland N-body problem

International Nuclear Information System (INIS)

Chen, H.H.; Lee, Y.C.; Pereira, N.R.

1979-01-01

The Benjamin--Ono equation that describes nonlinear internal waves in a stratified fluid is solved by a pole expansion method. The dynamics of poles which characterize solitons is shown to be identical to the well-known integrable N-body problem of Calogero, Moser, and Sutherland

The association between measurement sites of visceral adipose tissue and cardiovascular risk factors after caloric restriction in obese Korean women.

Science.gov (United States)

Lee, Hye-Ok; Yim, Jung-Eun; Lee, Jeong-Sook; Kim, Young-Seol; Choue, Ryowon

2013-02-01

Quantities as well as distributions of adipose tissue (AT) are significantly related to cardiovascular disease (CVD) risk factors and can be altered with caloric restriction. This study investigated which cross-sectional slice location of AT is most strongly correlated with changes in CVD risk factors after caloric restriction in obese Korean women. Thirty-three obese pre-menopausal Korean women (32.4 ± 8.5 yrs, BMI 27.1 ± 2.3 kg/m(2)) participated in a 12 weeks caloric restriction program. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were measured using computed tomography (CT) scans at the sites of L2-L3, L3-L4, and L4-L5. Fasting serum levels of glucose, insulin, triglyceride, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), leptin and homeostasis model assessment-insulin resistance (HOMA-IR) were observed. Pearson's partial correlation coefficients were used to assess the relationship between AT measurement sites and changes in CVD risk factors after calorie restriction. When calories were reduced by 350 kcal/day for 12 weeks, body weight (-2.7%), body fat mass (-8.2%), and waist circumference (-5.8%) all decreased (P restriction, serum levels of glucose (-4.6%), TC (-6.2%), LDL-C (-5.3%), leptin (-17.6%) and HOMA-IR (-18.2%) decreased significantly (P restriction.

[Anxiety and body image among women growing up in families with addiction problem].

Science.gov (United States)

Lelek, Agnieszka; Betkowska-Korpała, Barbara; Jabłoński, Marcin

2011-01-01

The aim of the study was to analyse the correlation between body image and anxiety symptoms as well as psychological discomfort experienced by women growing up in alcoholic families. The group of 61 women (27 years old on average) was surveyed with Body Self Questionnaire and MMPI-2 personality test questionnaires and the results were measured on Scale 7 (Pt). All the participants also attended psychotherapy sessions focused on disorders resulting from growing up in families with alcohol problems. The analysis showed negative correlation (p emotional spheres, as well as functioning cognitive schemes.

The annihilation diagram in three-body D-meson decay

International Nuclear Information System (INIS)

Donoghue, J.F.; Holstein, B.R.

1981-01-01

We discuss some features of three-body decays of the D meson cohich are puzzling from the standpoint of the annihilation diagram. As a result, we (1) provide an upper bound on the lifetime ratio of D's, tau + sub(D)/tau 0 sub(D) smaller than 2.5 +- 3.4 and (2) argue that the puzzles are resolved, even if somewhat inelegantly, if final state interactions generate the annihilation diagram. (orig.)

Shell structure of the A = 6 ground states from three-body dynamics

International Nuclear Information System (INIS)

Lehman, D.R.; Parke, W.C.

1983-01-01

Three-body (αNN) models of the 6 He and 6 Li ground states are used to investigate their shell structure. Three models for each nucleus are considered: simple, full (nn), and full (np) for 6 He, and simple, full (0%), and full (4%) for 6 Li. The full models in both cases are obtained by including the S/sub 1/2/, P/sub 1/2/, and P/sub 3/2/ partial waves of the αN interaction, whereas the simple model truncates to only the strongly resonant P/sub 3/2/ wave. The 6 He full models distinguish between use of the nn or np parameters for the 1 S 0 NN interaction, while the 6 Li full models have either a pure 3 S 1 NN interaction (0%) or a 3 S 1 - 3 D 1 interaction that leads to a 4% d-wave component in the deuteron (4%). These models are used to calculate the probabilities of the orbital components of the wave functions, the configuration-space single-particle orbital densities, and the configuration-space two-particle wave function amplitudes in j-j coupling with the nucleon coordinates referred to the alpha particle as the ''core'' or ''center of force.'' The results are then compared with those from phenomenological and realistic-interaction shell models. Major findings of the comparison are the following: None of the shell models considered have a distribution of orbital probabilities across shells like that predicted by three-body models; the orbital rms radii from three-body models indicate an ordering of the orbits within shells, i.e., p/sub 1/2/ outside p/sub 3/2/, unlike oscillator shell models with a single oscillator parameter where the p-shell orbitals have the same shape; and, as expected, three-body orbital densities decay at large radial distances as exponentials rather than the too compact Gaussian falling off of oscillator shell models

Intestinal perforation by an ingested foreign body*

Science.gov (United States)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F. S.; de Castro, Francisco Gomes; Miller, Wagner Peitl; de Lima, Raphael Rodrigues; Tazima, Leandro; Geraldo, Jamylle

2016-01-01

Objective To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. PMID:27818542

Intestinal perforation by an ingested foreign body

International Nuclear Information System (INIS)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F.S.; Castro, Francisco Gomes de; Miller, Wagner Peitl; Lima, Raphael Rodrigues de; Tazima, Leandro; Geraldo, Jamylle

2016-01-01

Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. (author)

Intestinal perforation by an ingested foreign body.

Science.gov (United States)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F S; de Castro, Francisco Gomes; Miller, Wagner Peitl; de Lima, Raphael Rodrigues; Tazima, Leandro; Geraldo, Jamylle

2016-01-01

To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation.

Intestinal perforation by an ingested foreign body

Energy Technology Data Exchange (ETDEWEB)

Nicolodi, Gabriel Cleve; Trippia, Cesar Rodrigo; Caboclo, Maria Fernanda F.S.; Castro, Francisco Gomes de; Miller, Wagner Peitl; Lima, Raphael Rodrigues de; Tazima, Leandro; Geraldo, Jamylle, E-mail: gabrielnicolodi@gmail.com [Hospital Sao Vicente - Funef, Curitiba, PR (Brazil)

2016-09-15

Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases), increased density of mesenteric fat (in all four cases), identification of the foreign body passing through the intestinal wall (in three cases), and gas in the peritoneal cavity (in one case). Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation. (author)

Intestinal perforation by an ingested foreign body

Directory of Open Access Journals (Sweden)

Gabriel Cleve Nicolodi

Full Text Available Abstract Objective: To identify the computed tomography findings suggestive of intestinal perforation by an ingested foreign body. Materials and Methods: This was a retrospective study of four cases of surgically proven intestinal perforation by a foreign body, comparing the computed tomography findings with those described in the literature. Results: None of the patients reported having ingested a foreign body, all were over 60 years of age, three of the four patients used a dental prosthesis, and all of the foreign bodies were elongated and sharp. In all four patients, there were findings indicative of acute abdomen. None of the foreign bodies were identified on conventional X-rays. The computed tomography findings suggestive of perforation were thickening of the intestinal walls (in all four cases, increased density of mesenteric fat (in all four cases, identification of the foreign body passing through the intestinal wall (in three cases, and gas in the peritoneal cavity (in one case. Conclusion: In cases of foreign body ingestion, intestinal perforation is more common when the foreign body is elongated and sharp. Although patients typically do not report having ingested such foreign bodies, the scenario should be suspected in elderly individuals who use dental prostheses. A computed tomography scan can detect foreign bodies, locate perforations, and guide treatment. The findings that suggest perforation are thickening of the intestinal walls, increased mesenteric fat density, and, less frequently, gas in the peritoneal cavity, often restricted to the point of perforation.

Body image dissatisfaction and dietary patterns according to nutritional status in adolescents.

Science.gov (United States)

Ribeiro-Silva, Rita de Cássia; Fiaccone, Rosemeire Leovigildo; Conceição-Machado, Maria Ester Pereira da; Ruiz, Ana Santos; Barreto, Maurício Lima; Santana, Mônica Leila Portela

There is a lack of data on the association between body self-perception and eating patterns in Brazil. Thus, this study aimed to explore the relationship between body image dissatisfaction and eating patterns by the anthropometric status in adolescents. A cross-sectional study of 1496 adolescents was conducted. The participants completed the Body Shape Questionnaire. Demographic, anthropometric, and socioeconomic data were collected, as well as information regarding the pubertal development and dietary intake. Logistic regression was performed to evaluate the associations of interest. Body image dissatisfaction was identified in 19.5% of the adolescents. Three dietary patterns were identified: (1) the Western pattern was composed of sweets and sugars, soft drinks, typical dishes, pastries, fast food, beef, milk, and dairy products; (2) the Traditional pattern was composed of oils, chicken, fish, eggs, processed meat products, cereals (rice, cassava flour, pasta, etc.), baked beans, and bread; and (3) the Restrictive pattern was composed of granola, roots, vegetables, and fruit. Among overweight/obese adolescents, the data indicated a negative association of slight body image dissatisfaction (OR: 0.240 [0.100; 0.576]) and moderate body image dissatisfaction (OR: 0.235 [0.086; 0.645]) with the Western dietary pattern. Additionally, in this group, there was a positive association between high body image dissatisfaction and the Restrictive pattern (OR: 2.794 [1.178; 6.630]). Amongst overweight/obese adolescents, those with slight and moderate body image dissatisfaction were less likely to follow a Western-like dietary pattern when compared with those satisfied with their body image. Additionally, in this group, adolescents with high body image dissatisfaction was more likely to follow a restrictive pattern. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Symmetry and geometry of the N-body problem. Application to the nuclear physics

International Nuclear Information System (INIS)

Chau, H.T.P.

2002-10-01

One of the main goals of classical and quantum physics is to solve the many-body problem. In nuclear theory, several methods have been developed and provide accurate results. In this thesis, we remind how symmetry can be used to obtain analytical solutions of the quantum many-body problem. We emphasize that unitary Lie algebras play a crucial role in quantum mechanics and propose and implement a method to build irreducible representations of this algebra from its highest-weight state. Calculations of bosonic and fermionic spectra are performed with realistic and with random interactions. Studies with rotational invariant two-body random interactions have unveiled high degree of order (a marked statistical preference is found for ground states with angular momentum equal to zero). In the second chapter of this thesis, it is argued that the spectral properties of this kind of interaction depend on the choice of the valence space. In particular, we propose a geometrical method to predict the properties of the ground state in certain cases. We also present numerical results when the geometrical approach can not be applied. In the third chapter, we study the link between quantum chaos and nuclear spectra calculated with realistic interactions. (author)

Highly eccentric hip-hop solutions of the 2 N-body problem

Science.gov (United States)

Barrabés, Esther; Cors, Josep M.; Pinyol, Conxita; Soler, Jaume

2010-02-01

We show the existence of families of hip-hop solutions in the equal-mass 2 N-body problem which are close to highly eccentric planar elliptic homographic motions of 2 N bodies plus small perpendicular non-harmonic oscillations. By introducing a parameter ɛ, the homographic motion and the small amplitude oscillations can be uncoupled into a purely Keplerian homographic motion of fixed period and a vertical oscillation described by a Hill type equation. Small changes in the eccentricity induce large variations in the period of the perpendicular oscillation and give rise, via a Bolzano argument, to resonant periodic solutions of the uncoupled system in a rotating frame. For small ɛ≠0, the topological transversality persists and Brouwer’s fixed point theorem shows the existence of this kind of solutions in the full system.

Nuclear many-body problem with repulsive hard core interactions

Energy Technology Data Exchange (ETDEWEB)

Haddad, L M

1965-07-01

The nuclear many-body problem is considered using the perturbation-theoretic approach of Brueckner and collaborators. This approach is outlined with particular attention paid to the graphical representation of the terms in the perturbation expansion. The problem is transformed to centre-of-mass coordinates in configuration space and difficulties involved in ordinary methods of solution of the resulting equation are discussed. A new technique, the 'reference spectrum method', devised by Bethe, Brandow and Petschek in an attempt to simplify the numerical work in presented. The basic equations are derived in this approximation and considering the repulsive hard core part of the interaction only, the effective mass is calculated at high momentum (using the same energy spectrum for both 'particle' and 'hole' states). The result of 0.87m is in agreement with that of Bethe et al. A more complete treatment using the reference spectrum method in introduced and a self-consistent set of equations is established for the reference spectrum parameters again for the case of hard core repulsions. (author)

Native Frames: Disentangling Sequential from Concerted Three-Body Fragmentation

Science.gov (United States)

Rajput, Jyoti; Severt, T.; Berry, Ben; Jochim, Bethany; Feizollah, Peyman; Kaderiya, Balram; Zohrabi, M.; Ablikim, U.; Ziaee, Farzaneh; Raju P., Kanaka; Rolles, D.; Rudenko, A.; Carnes, K. D.; Esry, B. D.; Ben-Itzhak, I.

2018-03-01

A key question concerning the three-body fragmentation of polyatomic molecules is the distinction of sequential and concerted mechanisms, i.e., the stepwise or simultaneous cleavage of bonds. Using laser-driven fragmentation of OCS into O++C++S+ and employing coincidence momentum imaging, we demonstrate a novel method that enables the clear separation of sequential and concerted breakup. The separation is accomplished by analyzing the three-body fragmentation in the native frame associated with each step and taking advantage of the rotation of the intermediate molecular fragment, CO2 + or CS2 + , before its unimolecular dissociation. This native-frame method works for any projectile (electrons, ions, or photons), provides details on each step of the sequential breakup, and enables the retrieval of the relevant spectra for sequential and concerted breakup separately. Specifically, this allows the determination of the branching ratio of all these processes in OCS3 + breakup. Moreover, we find that the first step of sequential breakup is tightly aligned along the laser polarization and identify the likely electronic states of the intermediate dication that undergo unimolecular dissociation in the second step. Finally, the separated concerted breakup spectra show clearly that the central carbon atom is preferentially ejected perpendicular to the laser field.

Unitary pole approximations and expansions in few-body systems

International Nuclear Information System (INIS)

Casel, A.; Haberzettl, H.; Sandhas, W.

1982-01-01

The unitary pole approximations or expansions of the two-body subsystem operators are well known, and particularly efficient and practical, methods to reduce the three-body problem to an effective two-body theory. In the present investigation we develop generalizations of these approximation techniques to the subsystem amplitudes of problems with higher particle numbers. They are based on the expansion of effective potentials which, in contrast to the genuine two-body interactions, are now energy dependent. Despite this feature our generalizations require only energy independent form factors, thus preserving one of the essential advantages of the genuine two-body approach. The application of these techniques to the four-body case is discussed in detail

Computerized assessment of body image in anorexia nervosa and bulimia nervosa: comparison with standardized body image assessment tool.

Science.gov (United States)

Caspi, Asaf; Amiaz, Revital; Davidson, Noa; Czerniak, Efrat; Gur, Eitan; Kiryati, Nahum; Harari, Daniel; Furst, Miriam; Stein, Daniel

2017-02-01

Body image disturbances are a prominent feature of eating disorders (EDs). Our aim was to test and evaluate a computerized assessment of body image (CABI), to compare the body image disturbances in different ED types, and to assess the factors affecting body image. The body image of 22 individuals undergoing inpatient treatment with restricting anorexia nervosa (AN-R), 22 with binge/purge AN (AN-B/P), 20 with bulimia nervosa (BN), and 41 healthy controls was assessed using the Contour Drawing Rating Scale (CDRS), the CABI, which simulated the participants' self-image in different levels of weight changes, and the Eating Disorder Inventory-2-Body Dissatisfaction (EDI-2-BD) scale. Severity of depression and anxiety was also assessed. Significant differences were found among the three scales assessing body image, although most of their dimensions differentiated between patients with EDs and controls. Our findings support the use of the CABI in the comparison of body image disturbances in patients with EDs vs. Moreover, the use of different assessment tools allows for a better understanding of the differences in body image disturbances in different ED types.